It seems to me to be a bad design choice: when I get tired, my decisionmaking capacity is impaired, and I'm likely to make decisions that result in my not getting the sleep I need.
Of course, if tiredness resulted in improved decisionmaking capacity, people would intentionally get tired in order to be able to make better decisions. But maybe if increasing tiredness resulted in more and more of the remaining energy being shunted into decisionmaking and other vital functions (Scotty, shift all power to life support!), perhaps the improved decisionmaking part would make the improved decision to sleep.
Or I might be babbling.
All this apropos of my having been unable to keep my eyes open for more than a few minutes at a time by late Friday night, at which point some stupid part of my brain had the idea of going shopping at the iTunes Music Store "just for a couple minutes" before going to sleep. "I know exactly what I want to get," said brain; "it won't take long." Ha.
So Friday night, which should be one of the best times of week for me to get lots of sleep, I actually got very little. (Loud Car Guy doesn't usually leave the parking lot on weekends, so I figured it was safe to sleep without earplugs (see above about impaired decisionmaking); I wasn't reckoning on a different loud car driving around the parking lot for several minutes at 7 a.m. Saturday.)
Fortunately, I'd gotten more or less enough sleep the previous couple nights, so Friday night the less-than-ideal amount I got was still enough to be safe spending much of Saturday driving. I drove to the Good Guys, where I found out that the part they told me last Sunday would take two days to arrive wasn't in yet. Thus, they couldn't install my new car stereo. Their installer guy isn't there on Sundays or Wednesdays, so I either have to go in before work some morning, or wait 'til next Saturday.
Mary Anne had suggested that if/when I move to a bigger place I should get some new furniture, notably an actual bed instead of a futon. So I stopped in at a couple of mattress places next to the Good Guys. At the first one, the middle-aged salesguy (who had oddly large and solid-looking and rough and callused hands, hands whose fingers were at least twice as thick as mine, hands I was inclined to think of as the hands of someone who's done a lot of manual labor but that might be middle-class romanticizing) (that detail, btw, is irrelevant to the rest of this paragraph; it just stuck in my mind because it set me off on making up stereotypical stories about him having worked his way up from being a mattress handler in the big mattress factories to owning his own store etc) was dubious of my claim to be just browsing (and not planning to actually buy a bed anytime soon), so (with just the right touch of humor, mostly; he was pretty good at gauging just how hard he could push without quite annoying me, and for most people he probably would've been a really good salesperson) he showed me the latest bed technology: springs that are encased in fabric cylinders to keep them separate from each other. Apparently this means that if someone on the other side of the bed is moving around, you won't feel it. Probably not a bad idea for as light a sleeper as I am, though I doubt it would help much with my difficulty sleeping in a bed with anyone else. Anyway, the springs are also slightly compacted, which the salesguy described as making them "like a loaded gun." Which didn't quite seem like the right choice of metaphor when you're talking about something built into a bed.
The next place was more comfortable for introvert me; the salesguy there was happy to let me browse without talking to me, and he had futons as well as beds (futons may only last half as long, but they also cost only half as much). If I do buy something new, it may well be from him.
Then I picked up Patrick and we headed off to workshop in Berkeley (about a 60- to 75-minute drive). Workshop went pretty well, I think. Then we dropped off Naomi down in San Jose (which turned out to be almost a 90-minute drive due to heavier than expected traffic), and I took Patrick back to Mountain View, and then I drove to the San Jose airport to pick up Kam (who was returning from a brief trip to LA), and then even though I was exhausted I drove to the Apple Store to get them to look at my iPod, which ever since I got it had been occasionally getting into a mode where it didn't respond at all to any input, requiring a reset. Not disastrous, but a hassle. So they replaced it. Unfortunately, the new one did exactly the same thing this morning, making me think the problem might be elsewhere, like in my FireWire cable or my earbuds or my body's electrical field or something.
Anyway, the upshot of all that was a lot of driving. Most of it was with cool and interesting people in the car and having interesting conversations, so I have no regrets. But glad to be able to sit around at home today.
Not being very productive today, alas; probably got enough sleep, but have a headache and am generally muzzy-headed. But I have a bunch left to do (including calling my father for Father's Day), so I better go do it.