I am somewhat of the same way with having a hunger for knowledge itself. I've found that what happens when I go from technology to technology isn't so much a re

I am somewhat of the same way with having a hunger for knowledge itself. I've found that what happens when I go from technology to technology isn't so much a reinvention as an augmentation. Maybe your experience has been different, but I've noticed an increasing depth in my analysis of systems, and I can't help but think that a part of this is due to the knowledge I've picked up in the meantime, even if it seemed tangential at the moment I learned it. To borrow some other authors words, it's partly why Peter Norvig, the Pragmatic guys, and ESR all push for people to learn different languages; your memory of the syntax might be ephemeral, but your internalizing of the concepts might change your thinking in ways you don't consciously notice. This poses an interesting, and very difficult, question to answer: how do you know whether something learned now will be useful in the future, especially if few other seem particularly interested? Over time you might develop an intuition for which things seem like they would be useful, but I can't imagine such an intuition would be perfect.