Bill,
My own history and two cents worth...
I've been where you are now. The "you'll probably need surgery in xx years" zone. Actually, I've lived most of my life in that zone.
I was diagnosed with aortic stenosis when I was 1 year old. My parents were shocked: "This human tornado of a child has a heart problem? Are you kidding me?"
As a kid, I participated, without reservation or limitation, in the following: baseball, football, tennis, competitive swimming, concert band, marching band, hiking, camping, fishing. You get the picture: just a normal kid who happens to have an unusual heartbeat and gets to visit a cardiologist and see all kinds of cool medical technology once a year. However, I know for a fact that responsible adults were watching very carefully.
That trend continued right through young adulthood, during which I participated, without reservation or limitation, in the following: concert band, marching band, softball, racquetball, volleyball, walleyball, broomball, apline skiing, hiking, camping, fishing. Again, you get the picture: just a normal guy who happens to have an unusual heartbeat and visits the cardiologist on at least a yearly basis.
At some point along the way, I started noticing shortness of breath during broomball (a high-exertion sport). Then an occasional chest pain during heavy exertion, but pain that went away with rest. Then the shortness of breath and/or the chest pains started happening after somewhat lower amounts of exertion. Then they started happening after some more "normal" amounts of exertion (like mowing or fertilizing the lawn). All along the progression to more-frequent symptoms I have carefully and completely described them to my cardiologists, and they have carefully and completely monitored the vital statistics of my aortic valve.
My current cardiologist is the one who moved me from the "you may or may not need surgery one day" zone into the "you will definitely need surgery in the next 3 to 5 years" zone about four years ago. That was a big shock for me, because I hadn't really thought I would get there. Most recently, I've moved through the "you'll need surgery in the next 6 to 12 months" zone into the "you should schedule surgery in the next 3 months, here's the name of a surgeon" zone. This has been less than a shock, because I knew what my advancing symptoms meant, and I got the warning shock four years ago.
I'll second all of the advice you've gotten from the others: 1) Visit your cardiologist regularly, 2) Learn what symptoms to watch out for, 3) Live your life as you normally would, 4) Report any onset of or changes in symptoms PROMPTLY to your cardiologist, 5) Don't worry about the "upcoming" surgery: it may never actually come up, 6) The better you maintain your health now, the better you'll be able to handle surgery, if-and-when.
I just de-cloaked in the waiting room a few weeks ago, but I've found it to be the most supoprtive, informative and amazing place!