I'm relatively new returning to cycling in November, 13 after about 43 years hiatus (making me 55 now). I started exercising and walking first, then got a step tracking device which made my competitive nature want to better the previous days' activity, so I was getting up at 5 AM to walk for 2 hours in order to accumulate 25,000 steps each day. I was at the point of doing nothing else, so bought a bike to get more exercise. I got the same energy burn in 30 minutes on the bike that I was 2 hours walking - plus, I genuinely enjoy riding.
A cousin, who's been into biking non-stop for pretty much all his 63 years, has been mentoring me on gear, technique and training. He signed me up to participate in a century coming due in October. A couple months ago I was worried about my ability. Working out in the gym 3 times a week and getting out for a 46 mile ride on Easter (and feeling fresh after it - as if I'd only done 10 miles perhaps) gave me enough confidence I signed up for a 2 day, 150 mile event.
I'm currently absorbing every bit of information in order to be a better cyclist, improve my health, and learn to maintain my bike more on my own. The technology these days is amazing! I have a gps, the heart monitor, feeds to strava, garmin, and training peaks, and just marvel at the statistics (my college degree) these things churn out. I'll never be a competitive racer by any stretch - but I will try to improve my own ability and try not to slow those I ride with down... too much.