My first reaction was to agree, but then I realized that couldn’t be so; it
would imply that I didn’t have rational expectations. Having attended services
for so many years, my overestimates and underestimates of their duration should
balance out: on average, I should correctly estimate their duration.
It’s possible that I might make mistakes if the world changed; and perhaps
our new rabbi goes longer than his predecessor. But even with that change, after
a few years I should estimate correctly on average. In fact, taking Friday and
Saturday together, I was correct: Friday night lasted only one and a half hours,
but Saturday’s service lasted half an hour longer than I expected.