relativity

When you are sitting with a good people (family, friends, colleagues, ..etc) an hour seems like a second, while when are sitting with a bad people a second seems like an hour; although it is the same hour (60 minutes) and you are the same one, but ur feelings with time depends on who are sitting with you. That's called relativity.
so imagine yourself is sitting with an angel comes to the earth for talking with you for a little, and you have to stay ONLY less than one hour with him;
how happy are you?! of course you will try to make use of every minute, no no , you will try to make use of every second in that hour. looking and listening to him, you will try close your eyes so it can confined him from going away; and at the end of that hour, you have to say I have to go now, you say it with ur mouth but ur mind and heart say what a fool man, what are you doing?
but sadly you know you can't stay more than one hour :(

In other hand, when u sit with a devile comes to earth to make a conversation with you, you wish the time pass quickly to end this conversation,
although you are the same one, but there are a great difference between the two feelings,
That's called relativity