At a wedding some years ago, while fantasizing about cutting the power cord for the DJ's mixer, I tried to come up with some icebreakers people could use in the sudden silence. The one I liked best was: "If you could go back in time and talk to your senior classmates for ten minutes, what would you say?"
That leads to "what else would you do?" and, recalling that I would be mentally older than my parents were at the time, heads straight into Something Wicked This Way Comes territory. You haven't read that one? Do. Now.
But speculating just for fun: what would I do if my current mind took hold of the senior class me, and I got the chance to try the rest of my life all over again?
Plus side: I get to fix some dumb mistakes. I made a lot of them. Some fixes are fairly generic and easy: get serious about exercise. Read less and listen more. The thing is, one of the mistakes was a choice of school: the right choice was over a hundred miles away. Changing the school makes a whole raft of other situations never appear. One of those situations was meeting my wife. Would I be able to stick it out wasting a couple of years? Worse yet, our age difference would be huge: would the intoxication be quite the same? Would other women be more like my Better Half as she is now than as the earlier version of her would be like the current version?
You'd think I'd be able to avoid the mistakes with the kids, and know the problems much earlier, but the kids would be different kids.
Minus side: I already know that stuff. Getting the necessary college degree would be horribly boring. Yes, I could be a star pupil, and get a better crack at the top jobs, but that might be over-reaching a bit.
I'm a researcher. We try to find out new stuff, right? If I already remember it, what's the point? Maybe I would take a whole different career direction: math instead of physics, or maybe a different branch of physics that I haven't kept track of so well, so that life would have a few surprises for me there.
I recall enough of the shape of history to avoid the big pitfalls, buy generally the right kinds of stocks (nothing in the mid 70's I didn't have any money then anyway, Cisco later), and be materially comfortable, but not rich. I don't think I could change history in any important ways.
And I think that after fixing the first major gaffes, I'd go on to make a whole new set of screw-ups. Maybe if this "going back in time" deal were iterative it might work: each time get a little farther along before screwing up too badly. Of course, what I think is the best life probably doesn't match very well with what God thinks.