I've noticed this at times about myself...I'm not very joyful.
As a Christian I'm convinced that I must be a joyful person; after all, joy is the 2nd fruit of the Holy Spirit! So why aren't I?
I believe it's because I forgot a perspective & that perspective is found in a song we sing around Christmas time every year:
No more let sins and sorrows grow
Nor thorns infest the ground
He comes to make His blessings flow
Far as the curse is found, far as the curse is found
Far as, far as the curse is found
This message coupled with God's Word & this line of JOY TO THE WORLD will help each of us have a perspective toward a renewed JOY!