Thought I'd relate 2 mental games to play to kill time when you need to (or to use in place of counting sheep).

1) Six Degrees Sorta: Pick two random actors and try to hook them up. For ex. Barbara Stanwyck and Johnny Depp:

Barbara Stanwyck + Clark Gable in "Night Nurse" > Clark Gable + Vivien Leigh in "Gone With the Wind" > Vivien Leigh + Marlon Brando in "Streetcar Named Desire" > Marlon Brando + Johnny Depp in "Don Juan De Marco"

2) Starting with AA, then moving to AB, AC, AD, etc., come up with people with those initials. For ex.,

Amy Adams
Adrienne Barbeau
Angela Cartwright
Adam Driver, etc.

Then move on to BA, BB, BC, etc. (I usually don't count the letters K, Q, X, Y, Z). Or you and another person could pick random letters which you yell out at the same time and use those.

If you have games like these -- car trip or waiting in line or falling asleep games -- let me know!