Why is it so difficult to fall asleep when you are overtired?

Is it really ? I go to sleep even if i'm overtired. I guess it just depends on the person.

it happened to me too and is the most annoying feeling ever! i hate when this happens is usually from coffee, even when the effect is over, and i try to go to sleep cause i feel really tired, my eyes just can't close

it is because you switched from fighting sleep and your body isnt ready yet

I don't know why is so difficult but sometimes it happens to me too, i just get home and i am too tired to fall asleep, can't explain that because usually is should get to sleep into an instant. Good luck maybe you will find the answer, or maybe we are too worried about some things to fall asleep and we keep thinking !