I'm not sure if that's an easy question to answer, but I can try...
40-somethings grew up in a world just discovering electronics as an every day thing. We went from transistor radios to solar calculators in a matter of a few short years, and everyone began marveling at the latest gadgets. Suddenly everyone on the block had the latest eye-popping item, whether that was the advent of cable boxes & MTV, or Simon, or cellular phones, or New Wave, or a personal computer (Apple II c or IBM), MS-DOS, Windows 3.1 or the latest MJ vid (or Square Pegs on TV).
We went from manual typewriters to electric to
personal computers in my lifetime.
From 8-Tracks to cassettes and mini-cassette players, and CDs, and from personal film reels to Betamax and VHS to LaserDiscs to DVDs.
Things that fascinated me growing up and made us all go, "WOW, NEAT!" are common place today. So common place, that people *expect* to have the latest, best, and newest gadget next year. In my opinion there's no innovation for something "new"...it's simply an upgrade of last years' model.
Maybe I miss the "wow" factor of innovation. Really, create something I've never seen before; something I need. And don't put it on an infomercial at 5am.
What does it mean to be 40-something? It means recognizing that you aren't the person you thought you were, which could be a good or a bad thing (depending on what you thought yourself to be). It means a new level of maturity within yourself, and the confidence to pursue those things you never considered before. It means drawing closer to your family or watching family members grow up and leave the nest to make families of their own (I suppose; I don't know this part but I assume it's true). It means facing your own mortality when you begin feeling twinges you never felt before and suddenly seeing your parents grow "old" seemingly overnight.
But to me, it's fascinating. Like seeing a butterfly you've never had the chance to observe before...and realizing that butterfly is you.