Bart...today your mother and I were called to the school again because you were causing trouble. You started a rumour that the teachers were scanning the kids brains to turn you all into zombies and convinced half the students to wear tinfoil hats whilst you staged a protest outside. Principle Skinner told us that you are running out of chances, though to be fair he's been saying that for years and hasn't kicked you out yet.

I know I should say I am disappointed in your behaviour, that you need to learn some discipline but I won't. Partly because I'm used to it by now and partly because I was never much of a model child myself so I can hardly judge. It's something you and I have in common, though I know you would hate the idea of having anything in common with me.

But you do. Lots of things actually. And that's not as bad as you might think.

My biggest joy is that you inherited my 'give it a go' attitude. That little voice inside that tells you to take a chance on things no matter how ridiculous they seem. That's why when I come up with all those daft plans and schemes that drive your mother mad I like to take you along, because I know that you will be right there with me, willing to give it a try even when everyone else is shaking their heads in pity or disbelief. I love those times. Even if we fail, I love being able to share those moment with you. I hope you do too.

This trait probably won't make you rich or successful...it never did for me at least...but it will lead you to experience things most people never will...driving you to accept opportunities as they come that most would ignore in favour of more sensible, logical paths. You won't understand right now but there is a value in that. I am not a rich man son, but I have led a rich life filled with adventure and experiences that will stay with me forever and believe me...that is priceless.

I hope that you will live a life like that too.

I'm sure you will.

More than that you have a gift that you didn't get from me. One I admire and envy. One you use all the time but probably aren't even aware of. One that you used today.

Even as we entered the school where you were being kept in the principal's office, isolated from the rest of the students, your mother and I passed dozens of students still wearing their hats, chanting for your release.

You have a talent Bart. Not for trouble like Skinner claims...

For leadership.

You inspire people. You always have. You have a charisma that draws people in and makes them believe in you no matter how crazy the things you tell them are.

I was never like that. Never able to sway people to my way of thinking so completely. Don't underestimate how extraordinary it is.

I know your mother worries for you. For your future. But I don't. You are young and full of restless energy but time will take away the worst of that and leave behind a young man with the power to do anything he sets his mind to and a mind that will see opportunity around every corner...I know that no matter what happens you will be alright. You will live a good life as I have done and some day boy, you will do great things.

I know I don't say this often enough...but I'm proud of you.

Lisa...today you built a soundwave spectrometer out of an old phone, a camera, and a hairdryer. I only know that because I copied the name from the notepad on your desk and your mother has been searching for her hairdryer for the last hour. I'll keep your secret though...and buy her a new one tomorrow.

I have so much I need to say to you, but the first and foremost one pains me, because it means admitting once and for all that I let you down. What I need to say is...

'I'm sorry Lisa'

I'm sorry that I was never the father you needed. I'm sorry I didn't take the time to truly bond with you when you were younger, always too busy with work or with Bart.

By the time I was ready to be there for you, you no longer needed me.

My fierce independent little girl.

I wanted to hold onto you. I don't want you to ever doubt that. I know that there was always a kind of distance between us and I am so sorry for that, but never for a moment believe that I didn't love you with all my heart. I did. I love all of you more than words can express. But you were so exceptional Lisa. So far beyond anything I could ever have imagined. I wanted to hold onto you...but I couldn't...I would have only been holding you back.

For now you are still young and there are times now and then when you still ask for my help, even if its only something simple like needing me to drive you somewhere. I don't know if it shows but I love those moments. Those times when I can still be of use to you. Can still take care of you as I should.

Soon enough you wont even need me for that. I'll make the most of it while I can. Be there for you in whatever way you need.

Please remember, no matter how high you climb, I will always be here for you if you need me, ready to catch you if you fall, though I doubt you will, my clever talented girl.

I wish that I could have been more for you. Been clever enough to support you when you needed it. Been a father you could have been proud of.

I wish that I could stand by your side as you rise up to greatness as I know you will. But although I can't, I want you to know that from where I stand, far below you, always looking up, you look absolutely beautiful. My shining star.

It is a privilege just to bear witness to all that you are.

Maggie...today I rocked you to sleep in my arms then watched over you as you slept. In fact I am sat beside you now as I write this letter, watching you shift slightly as you dream. I hope they are good dreams. Filled with innocence and joy.

I don't know what prompted me to check in on you all those nights ago. A strange impulse that drew me out of my bed, urging me towards you, a fatherly need to see that you were alright, but it led me to a realisation that changed my world in a way I will never regret.

You see your mother thinks you sleep right through the night, from the moment she puts you down to the moment she wakes you up. A perfect angel.

But I know you don't. I know that once she leaves, you wake again, lay there quietly in the dark, gazing up at the mobile that hangs above your bed, until finally the rest of the house settles down and in the quiet hours of the evening I can come and lift you into my arms and rock you to sleep for a second time undisturbed.

Sometimes I place you back down as soon as your breathing evens and leave you to your rest, but most times I will keep hold of you, gazing down at your peaceful face, swaying back and forth and wishing that the night would never end.

I treasure those moments.

Our moments.

Even more so because I fear that they are numbered.

You are growing so fast my sweet. Soon you will have grown enough that you will no longer need me, just as your brother and sister have. But like them, I will always be here for you.

I wonder sometimes who you will grow into. Will you be spirited and boisterous like Bart? or clever and independent like Lisa? or will you be something else entirely? something purely you?

I fear the day I no longer get to hold you like this, but at the same time I can't wait to find out. To see you grow into the remarkable person I know you will be.

There will be days to come when you look at me with anger, other days with frustration, others still with disappointment. I am not the world's greatest father though I'm trying to be better.

But for now you don't know that. For now you look up to me as I lift you from your bed each night and hold you safe in my arms, and you see in me the father I have always wanted to be. And when those future days come I will hold on to that memory. That look in your eyes.

I will do everything I can to keep that look there as long as possible, to be that father.

The father you all deserve.

To my children.

For all our ups and downs I want you to know that you are the greatest thing I have ever done and I am honoured to be your father. I promise that I will do right by you. All of you. That I will try as hard as I can to provide and care for you, to give you everything you could ever want or need.

I am not the world's best father, but I promise to try every day to be the best I can be...for you...all of you.

My boy,

My little lady,

My baby girl.