Hi Jason and your among friends as I also had the same thoughts when I got my pacemaker now over 15 years ago. I had it for 10 years and served me well. But to relive your concerns, at the time I was about your age and after the light duty period was over I went back to a job I loved, working on towers and mountain top communication sites. No problem doing the job and had the confidence that the pacemaker was watching out for me 24/7. Ultimately my heart got worse and I needed to get a transplant, but the pacemaker gave me the time I needed to get closer to retirement age and was a great help in giving me the care I needed when my Heart would have issues. As others have said now that the technology has advanced, I can imagine that what they can do now are even more advanced than the 2 I had during my 10 year period.
So if I can help with any questions please ask away.