losing track of time
Have you ever been so absorbed in some activity that you lose track of time? How good is that?
Be it playing a game, reading a great book,a really deep meditation session or having a conversation with a friend for few hours but you never felt the passage of time. This feeling of completely committing something, it feels good.
Whenever you feel that way, remember what you are doing and do it again because it's good to lose yourself from the world. If you can do this at will, your life will be so much rewarding. Don't ignore the activity that you do in this 'flow state'.
A good time occurs precisely when we lose track of what time it is.