Okay, for once, I'm going to have to agree with Patrick about starting times.
I am usually fine with a 8 p.m. start. I see from the Tales of Hoffman page at San Francisco Opera's web site that most weekday performances of Hoffman are starting at 7:30, but not the Friday night. People, by Friday, many of us are a little tired from our day jobs. In the mid-90s, when I didn't have a commute to speak of and I was 18 years younger, 8 p.m. on a Friday wasn't a problem. Now that I'm up around 6 a.m. and have a long, long commute, well, let's just say that I understand why the Friday audience is a little more subdued than the Sunday audience.
I really wish the show had started at 7:30. As it was, even with very short intermissions, Hoffman finished at 11:30 and it was 12:40 by the time I got home. You'd think it was a Wagner opera.
I also was not feeling great, having had a little too much cheese at a party at work and not having gotten enough sleep during the week. Before the opera, trying to figure out where to have dinner, I actually avoided a possible encounter with someone I know; under other circumstances, I would have been happy to say hi and chat with him. I seriously considered skipping the opera altogether, and was sufficiently jammed in during the first act that I thought about leaving even though I liked what I was seeing and hearing.
Okay, obviously only part of the problem was the 8 p.m. start time. That'll teach me to overindulge at TGIF.