Who let the meme sheep out?

Pick a character* I've written and I will give and explain the top five** ideas/concepts/etc I keep in mind while writing that character that I believe are essential to accurately depicting them.

* Try to make it someone I've written either often (including characters I RP'ed) or recently in order for me to answer. [My addition: you don't have to! But if I've only written them once or twice, you'll probably get a shorter answer, and I may be coming up with it off the cuff.]
** May not actually be five.