Scenario:
2 students are in the same class listening to the same lecturer.
At the end of the class student A claims that the time went by so fast he didn't realize an hour had passed. Student B claims that the time went by so slowly that he was sure 3 hours had passed.

Could it be that for each student the amount of 1 hour really went fast for A and slowly for B? Or is it something else?

Relativity. To quote an awesomely bad movie, Deep Blue Sea:

"Grab hold of a hot pan, second can seem like an hour. Put your hands on a hot woman, an hour can seem like a second. It's all relative."

A show called Brainiac Science Abuse conducted an experiment. They took two guys off the street, and gave one a massage and a steak dinner, and the other had to peel potatoes. They both carried out their tasts for the same period of time, 40 minutes.

The guy who had the massage and dinner felt he was only there for 25 minutes, whearas the other guy felt he was there for over an hour.

I think it's to do with enjoying how you're spending the time. If you're doing something you love, the time will seem to go quicker than if you're doing something you dislike.

Depends on if the class was interesting or not. It pretty much is the same for work days, if I'm busy I don't notice the time ticking away but if it's slow I'm wondering how much longer before I can leave.

Time is constant but our perception of it is relative.

Einstein said that.

Einstein talked about grabbing a hot woman?

I know it's Einstein, I was using a more contemporary version.

"Put your hand on a hot stove for a minute, and it seems like an hour. Sit with a pretty girl for an hour, and it seems like a minute. THAT'S relativity."

Grabbing no, but close enough.

So none of you actually believe that time is actually different for each person, disregarding relativity?

Yes, I think our perception of it is the only thing different, but it's the same thing. And here goes Sui, telling me "time in and of itself is all perception". Let me drag him here