[quote=@Legend]
<Snipped quote by Intrepid>

I've heard of that, and I understand how caffeine work biologically, but what exactly does it feel like?
[/quote]

Energizing? I dunno the best way to put it, but it definitely heightens your senses and makes you feel more energetic... You mentioned drugs earlier, though. Caffeine does kind of fit that bill. A chemical we ingest to achieve an intended feeling and effect.