I'm somewhat less enthusiastic with Traveller's future history than you are, but I've been told that a history degree is an invaluable GMing resource, and judging from my own mental trajectory, I'm of the opinion that creativity diminishes as we age. There are probably ways that we can "hack" our creative process to extend its usefulness, but my advice, for what little it's worth, is that you should write down as much now as you possibly can, because there will come a day that it will fade.