[ehnto]

Caffeine doesn't necessarily stop everyone from sleeping, but it has been shown to still affect sleep quality if you do manage to get to sleep. It also might be that you're falling asleep before the caffeine has a chance to interrupt your sleepiness.

I felt the same way as you and would often have coffee before bed, but since stopping that practice I feel much, much more rested. I stop 6 hours before intending to go to sleep, since that's about the half-life of caffeine in the body. Everyone is probably a little different in their ability to process caffeine, but this has been working for me.