So yesterday, it occurred to me that I probably knitted about 5 hours. Here's how I reckon it: an hour on the commute, a half-hour walking to lunch, another half-hour scattered about through the workday, fifteen minutes while walking to the knitting class, two hours during the knitting class, and an hour at home after the knitting class (maybe more).
I have found that prolonged activity doing something very specific and intense causes my brain to go into "drunk" mode. This first occurred to me several years ago, when my wife (then girlfriend) came over for a visit immediately after I had spent the past three hours fiddling along with Louis Boudreault recordings (without a break). About ten minutes before she arrived, my brain had had enough and sent me into a stimulation overflow, so I put down the fiddle, collapsed onto the couch, and stared at the ceiling. When she came over, we walked over to the grocery store, and it was very obvious to her that I was acting as if I were drunk. Slurred speech, stumbly steps, random comments... the whole bit.
So, this happened to me again last night, only it wasn't quite as pronounced as was the fiddling episode. She thought I was drunk again, and I told her that I wasn't drunk but rather had knitted too much. It was more of a dazed feeling than anything else, and it wasn't really unpleasant. I wonder if this is a common phenomenon among knitters.