(A more sincere answer might be, because when I was your age the meds we both need didn't exist and we all learned pretty fast that the only other way to gain the approval of the adults and systems around you was to crank your imagination up to 11 and self-medicate on whichever half of your own fight or flight response was the most accessible that day.)
How long have you got?
how about: "an abundance of talent, mixed with an effervescent sense of humor, and a generous serving of stubbornness and spite"
usually, when my family asks *me* why i'm like this, my response is "i haven't been able to hire anyone else able and willing to be like this".
"Environmental pressures, genetics, pure meanness," is usually how I respond to that question.
<3