Have you ever been hard-at-work on a project and then glanced at the clock and realized 5 hours had flown by, but it only felt like 30 minutes? And you were so in-tune and focused that your perception of time made the hours evaporate? Conversely, have you ever sat in a class where every minute felt like an eternity; and you kept staring at the clock yearning for it to be over? I'd choose the first option any day of the week...