He can't be expected to do work that matters because he has no authority.
She can't rise above mediocrity because she comes from underprivileged family.
He can't create change unless he solves his long term health issues.
She can't contribute because it's someone else's job.
He can't say "yes" because it might fail.
She can't make mistakes because so much is at stake.
He can't teach, inspire, and lead because he has no right education.
Who knows a person who was generous before but changed after having a baby? I don't.
If we focus too much on "can't", we will miss opportunity to change the world (around us).
PS My friend Steven Monrotus had more than enough reasons to focus on "can't" when he wanted to learn to create an organ processional. Instead, he focused on "can" part, followed my lead from these video tutorials, and created a Recessional in D which he can be proud of (and is already working on his next composition). Here is the score, if you want to play it or join the club of creators (this piece is for manuals only).