Should be a pretty easy task. You've been with yourself since the day you were born so it shouldn't be hard to know who you are. And yet...
Knowing yourself is harder than it looks. At least it is for me. Maybe it is for you, I don't know. It's hard because we're an adaptable species, we settle into routines very easily and we think we like things simply because we're used to them.
Truly knowing yourself requires time and dedication. Also requires that you question everything you think you already know about yourself. And that's a hard thing to do.