The odd thing about most of the learning you do during the clinical years is that you don't know you're doing it. I mean, in basic science, you can go home and say "today I learned the Krebb's cycle". In the clinical years, it's more like one day you realize, "Wow, I actually know what to do about this," or "Wow, I'm not struggling with presentations as much as I used to." On a day to day level, though, you often feel "Ugh... all I did today was run around seeing another patient every 15 minutes, and I didn't even get a chance to read about half the things that came up." or, on an inpatient rotation, "Ugh, all I did today was find films, round for five hours, draw blood, and get coffee for my team! When are they going to teach me something in exchange for all this scut? This is so useless."
That said, some rotations are more high yield than others, as previous posters have pointed out.
Best,
Anka