Tea query

So, um, does tea put anyone else to sleep? I'm talking about caffeinated English Breakfast, not Sleepytime or camomile or some such.

I had several cups of strong tea this afternoon, and shortly after the stimulation left (visitor), I found myself looking at my sudoku cross-eyed. I put my head down on the table for kicks, and found myself waking up a short while later when Babe made a loudish noise.

So, I then went to crash on the infinitely more comfortable couch. (Nice thing about lying about on the couch with Babe around, is that I know where he is at all times even with my eyes closed: Climbing over me!) I think I had an hour's lie down. And that's how it is just about every time I drink the stuff!

Isn't it supposed to perk you up?