People often advocate for staying away from your bed for studying, because your mind subconsciously associates bed with sleeping. Or at least should. If you spend too much time studying on your bed, you may find that you can't sleep on your bed easily. Same if you sleep a lot on your bed, you may find that you can't study well there without becoming sleepy. Each place becomes associated with different things, separate. Each is a specific type of "oasis," so to speak, from the rest of the world around it. Need some sleep? Go to your bed "oasis." Food? Off to the kitchen "oasis." There is an oasis of some sort or another for ever activity.
However, this can sometimes even be a problem. What happens, for instance, when you've long ago associated a specific location with a certain activity, but as the years pass, your interest in said activity wanes? When you go back to that location, that activity is what dominated you there, and that is what your interest there is. It becomes hard to do anything else in that location, because all your mind turns to is what you used to do there. Had a favorite spot on the couch where you used to watch TV, but now want to use it to read? Well, that might explain why your mind is constantly thinking about whatever TV shows might be on while you're sitting there, no matter how engrossing the book. The force of habit and association is a very strong one.
Every location in our lives is an "oasis" of some sort, but each can be a pitfall, too. It all depends on what we make it. Associations occur, so we should be cautious in our lives about what things we associate with certain activities. Sometimes it happens intentionally, sometimes purely by accident, and sometimes we don't even realized it's happened until we go back. You will find, though, that those associations do occur. So choose them well and make them good!