I can relate to the amped up feeling. Alcohol really felt more like a stimulant to me. My energy and alertness increased after a few drinks. I also became very engaged in what was doing in a weird, drunk way. Painting an entire room (taping and all) was so easy when drunk.
However, my tolerance became nearly bottomless. Often I felt barely buzzed sober after ten drinks. God, I was one sick puppy. The amped up feeling led to blackouts and fits of rage and sobbing. Never again.
Btw: I know darn well I was not actually more alert but it sure felt like it! I think it just calmed my central nervous system, like putting the car into cruise control.