When you were 5, your mom gave you an ice cream cone. You thanked her by yelling at her that it's the wrong kind, because it was the one she ordered. You switched and laughed.
When you were 9, your mom drove you from swimming class to soccer and one birthday party to another. You thanked her by slamming the door and never looking back, because you were busy buckling up and yammering all about your day to your mom.
When you were 10, your mom payed for piano classes. You thanked her by never coming to class, because your teacher, who came to your house for lessons, became your best friend and you practiced together in your living room so your mom could hear everything.
When you were 12, your mom was waiting for a very important call. You thanked her by talking on the phone all night, because the phone call she waited for was the one from you when she was away on a business trip.
When you were 14, your mom payed for a month away at summer camp. You thanked her by not bothering to write a single letter, because who needs snail mail when you have Facetime, Facebook, and Skype?
When you were 16, your mom taught you how to drive her car. You thanked her by taking it every chance you got, especially when your younger siblings needed a lift. You'd be their chauffer and give the poor lady a break.
When you were 17, your mom drove you to the mall and gave you her credit card. You thanked her by maxing it out, because that fun card and pretty dress made a really great Mother's Day gift.
When you were 18, your mom cried at your high school graduation. You thanked her by partying until dawn, with her and all the others who helped you get there.
When you were 20, your mom drove you to collage. You thanked her by saying good-bye to her outside the dorm so you wouldn't have to say bye in front of your friends, and so she wouldn't see your bawling face when you collapsed inside because of how much you were going to miss her.
When you were 26, your mom payed for your wedding. You thanked her by moving halfway across the world, and it was the hardest thing you'd ever done, being so far away.
When you were 30, your mom fell ill and needed you to take care of her. You thanked her by reading about the burden parents became to children, and vowing you would not be like that, and be like your mom instead.
Then, one day, she quietly died and everything you did came crashing down on you.
Crashing? I don't think so. Those good memories are the only reason you could keep going with a smile.
I found the version of this for moms, and just had to do a repeat performance. I tried not to do it the same way, and some of the things might be hard to understand, but a lot of this comes from my childhood and my sibling's, so it's really close to me.