[j2kun]

I literally study the proofs of others every working day, for at least a few hours a day. But I am a young mathematician and still inexperienced with research.

I imagine that once you are a professor you can spend less time studying the details of proofs because you can generate them on your own once you understand the big picture. But even so this depends on your field (combinatorics folks, for example, REALLY spend a lot of time studying proofs).