Time...

Why is it that kids use time to their advantage even before they know how to tell it!

If I ask Riley to clean up and tell him he has 5min he automatically will try and bump me to 10min and when time is up he claims that it isn't. The opposite is also true, when Riley would like me to do something and I tell him 1min or 5min it's as if his clock works twice as fast! 20 seconds will have passed and he will be telling me time is up......boy let me tell you, today I'm sure glad it's almost "bed time"!