U probably won't notice how buzzed you are until you THINK you are ready to go to sleep, you'll lie in bed and thats about it, you'll be tossing turning, having random thoughts, mind starts racing, next thing you know its 4 0'clock and you still can't bat an eyelid. I personally like to take speed with other stuff, like pills or alcohol, as i seem to get the best out of both, (i know its dangerous, but drinking on speed i can drink like a fish, lose my inhibitions like alcohol normally does to me, but remain clear headed, and have no hangover) i find speed on its own, in small doses doesn't really do much, except pick me up a little.