I'm only 27 so take this with a pinch of salt but I'm finding that true "insight" tends to take the form of making connections between seemingly unconnected things. To make these connections requires that you have, of course, an inquisitive, sharp mind, but also a broad knowledge-base to pull from.
So don't limit yourself to one discipline. If you're into comp sci, don't just read comp sci papers. Try some humanities or even art from time to time. The most unique ideas seem, to me, to come from taking knowledge from one field and adapting it into another. I've learned so much by taking a casual interest in fields unrelated to what I do and certainly feel "sharp" when I see connections between things I'd be otherwise ignorant of if I were a "specialist."
So don't limit yourself to one discipline. If you're into comp sci, don't just read comp sci papers. Try some humanities or even art from time to time. The most unique ideas seem, to me, to come from taking knowledge from one field and adapting it into another. I've learned so much by taking a casual interest in fields unrelated to what I do and certainly feel "sharp" when I see connections between things I'd be otherwise ignorant of if I were a "specialist."