+1 to what everybody's said, and some more info (tho' no childhood OHS):
Pain control in hospitals these days is a @#$%& MIRACLE compared to only a decade or two ago. I recently lost a sister to "cancer of the everything", and her pain was controlled so well (in the hospital and later at home) that she recommended her drugs to me and a few others. So you're allowed to worry about having major surgery, but worrying about the pain is just a waste of time. In addition, many of us actually had shockingly low levels of pain. I was shocked, for one.
There's another factor that gives you a huge advantage this time from when you were a child: You are an adult, with a good understanding of what's happening, with a professional relationship with your care providers (like, you chose them and hired them to do this work for YOU), with a lot of control over what happens (including the pain-killers).
Years ago, I had an experience that convinced me that the kind of understanding and control that's been added to your situation since you were a child is POWERFUL like MAGIC, and I've seen it proved several times since! The first time, I was flying out of Toronto, maybe to Boston. I think it was soon after Christmas holidays. It became obvious before takeoff that most of my fellow passengers were returning home (not to Boston, my guess was Portugal) after visiting family in Toronto. Most of them spoke no English and no French. The nice folks from Air Canada explained all the procedures to us in both of Canada's official languages, and these folks basically heard "Blah, Blah, Blah".
As luck would have it, we hit a bunch of turbulence, and the announcements came on the PA to explain it, in English and French, NONE of which most of these nice folks understood a word of! None of the flight attendants seemed to speak Portuguese, and precious few of this group of passengers spoke French or English. To the people who understood the announcements, this was a temporary problem, well explained by confident-sounding and courteous professionals; to the people who understood little or nothing, it was bewildering, while we were all being tossed around in a big aluminum tube WAY up in the air.
The outcome was amazing to me at the time: Essentially NOBODY who understood the announcements got sick, and EVERYBODY who DIDN'T understand them, hurled into the white bags (or somewhere)! Just being in communication with the staff in a professional way, like grownups, saved "us" from tossing our cookies. Because we were being treated like grownups (and people who couldn't understand the announcements couldn't be), the same turbulence was a nuisance, but not a terror. (I've since seen the same effect on my sailboat, where the people who understood the situation didn't get sick and the young kids and the total landlubbers were quicker to get sick.)
In addition to the advances in techniques and equipment and drugs since 1972, you'll have the benefit of entering this surgery as a grown-up, with some control over your situation. If you want to be knocked out a lot, and/or to get the anti-anxiety drugs that also make you forget the surgical experience, just tell that to YOUR anesthesiologist. (I didn't want that, and I explained that to mine, but that's me and you're you!) If you have pain, or nausea, or whatever, just tell YOUR staff, and they'll do something about it. And unlike you as a kid, you can go into this whole thing with 100% confidence that all the people around you will be working for you -- not just trying to fix your heart even if it hurts like Hell, but responding to you so you're not in pain.
It's still not a picnic, and "bumps" on the road do happen, but nobody remembers the surgery, and the post-op recovery is mostly a series of improvements. Most of us were walking by a day or two post-op, which is a miracle, given how invasive the surgery is.
Just one more thing: When you're anticipating these things, your mind is free to wander and drive you nuts. When you're actually in recovery, you're THERE! It is what it is, and the only choices are to cope with it or. . .? You've probably encounters some crises in your life that were actually tragic (unlike this one), and I bet you got through it better than you would have dreamed in advance. That's what people usually do when faced with an actual crisis. And when you're actually post-op, you'll be surrounded by people taking care of you and giving you stuff and listening to your concerns. I don't know about you, but that doesn't happen to ME all the time!
