I am about to start my third year in studying mathematics and it has never been required of us to do background reading. I really like the subject and there are some aspects of it (as well as a tiny bit of physics) that I have an inclination to find out more about. However, I've simply not bothered with background reading because I would rather do something that makes me feel happy, I have managed to get a first in all but one of my modules so far without that much of it, and when I read too much unfamiliar content for too long my mind tenses up.
I feel like I should be doing A LOT more background reading but I simply don't feel like doing it. I am also doing a Masters course at the same uni (and I also want to do a PhD) - how can I ease myself into getting into this habit without making me feel like I have to do it for the sake of it? I also get the impression that I need to do more background reading if I want to go further on in academia...
Well you said there are certain areas you are interested in so you should start there.
But if you are so interested in your subject that you want to do a PhD then surely a bit of extra reading won't be too much of a chore? Though if you're getting 1sts all the time I can see why it could be hard to motivate yourself.