OK, 'compression' is the wrong analogy as it implies that we don't lose any information. I'm not sure this is always a bad thing. I might have use of a particular theorem. Being the careful sort, I work through the proof. Satisfied, I add the theorem to my grab bag of tricks (yay product rule!). In a couple of weeks (hours even...) I have forgotten the details of the proof, but I have enough confidence in my own upvote of the theorem to keep using it. The details are no longer relevant unless some other evidence comes along that brings the theorem, and thus the 'proof' into question.