Mistakes. Stupid, stupid mistakes. Usually not meant to cause harm, but can sometimes hurt more than mean intentions can.
I know a lot about mistakes. At least, others seem to think so since it is my advice they seek out, especially Kitty. It doesn't put a lot of faith in my abilities.
Mistakes are easy to forget when it's as easy as hitting the clear button on a calculator when you typed a four instead of a seven because you're sick of math. Mistakes are easy to forgive when well intentioned, like accidentally dyeing the Institute's white tablecloths and unflattering pink when you didn't see the red napkin thrown in too. At least Charles finds it too funny to buy new ones, deciding instead to chuckle at the beginning of every meal.
There are some mistakes, though, that can't be fixed. Such as, getting disowned by your extended family because you called your Aunt Patricia a prejudiced sanctimonious bitch over Christmas dinner. Especially when, after they protested in her favor instead of yours, you called the rest of them a herd of hypocritical assholes. The cops end up getting called and you spend a night in lock-up. Your mother is still angry with you for it.
Or when you threw the frisbee a little too far when playing a late afternoon game of catch with your best friend, even though you never expected it would result in her death and the beginning of your mutation. You still hate yourself for it, and so does Annie's mother.
Or when Ororo killed five civilians in a battle with the Sentinels two years ago. She still visits their graves.
Or when Scott cheated on you one time he's too drunk to remember clearly and hates himself for.
Or how you didn't take him back.
We could have worked it out. After six years of dating, we could have figured it out, but instead, I broke both of our hearts.
I've made a lot of mistakes in my lifetime, but my single biggest was letting the man I love go.
This one-shot has a companion, Haunting Regrets, from Scott's perspective.