There are always challenges. I wouldn't want it any other way. I am fond of challenging myself, and usually, there are plenty of outside challenges to keep me occupied.
Sometimes the challenge is just getting my day together before it runs away with me.
Sometimes it is mastering (or just learning) a new technique, or a technology application.
There are times when it is challenging to make myself relax...in the face of so much to do.
Then there is that challenge of making myself do something I need to do and don't really want to.
What do you see as a challenge? How do you challenge yourself?