I think that most would find themselves reflecting on good things, however and unfortunately, there are some that can only reflect and think of the bad things.
The apostle Paul wrote in Philippians 4:8;
"Finally, brethren, whatever is true, whatever is honorable,
whatever is right, whatever is pure, whatever is lovely, whatever is of good
repute, if there is any excellence and if anything worthy of praise, dwell on
these things."
This surely beats the alternative!