This may sound weird, but I think I learn best and I'm (a bit more) productive when I'm doing things I shouldn't be. Let me explain. In Psychology today I had just remembered that I had to finish a French booklet on the passé composé that is due tomorrow, and I was bored and stuff, so I just started working on the booklet. I got through more in the booklet in the last 20 minutes of my psychology lesson than in the approximate week since I had gotten the booklet. Is this actually a thing? This also happens when I'm studying Japanese for my tutor in other classes, like one time I had a double R.E. lesson and it was just boring stuff and nothing, and I spent that two hours studying for my next Skype lesson with my sensei, and it was so productive! I know this may not be the best method of getting things done, and I could be missing things (but I record the audio of the lesson anyway), but it works for me, and nothing else seems to work for me. I'm a procrastinator at heart XD
I don't think this is weird at all; I feel the same way. My theory is that you get things done more quickly when you're doing the thing when you shouldn't be because you actually want to do it. When you're bored in class, you'd rather do other work, so you pay more attention to it and do it faster because you want to do it. This as opposed to having to do it at home when you'd rather do something else.
You get bored, so you do something else, and you do a good job. Is there anything not normal about this situation? It's human nature.