Because my brain isn't big enough to contain it all.
Room for Improvement
"You've lived life long enough to know that nothing -- and no one -- is perfect. So why are you holding yourself to such an impossibly high standard? What you have right now, what you're doing right now and (most importantly) who you are right now is good enough! Cut yourself some slack. If you spend all of your time wishing you had more, the universe might take away what you have. Be grateful for the fact that you have room to improve."