I've been on the water for 43 years and know exactly what davidpm is talking about. It's very easy to stay in the comfort zone. I too have done some of what he's done. We basically set sights on a new goal that is achievable
and then plan toward it. One year, the Dismal Swamp Canal & Ablemarle Sound looked interesting, another year it was a trip nearly the length of the Bay. In between, it's setting off at sunset for a 15 mile cruise to a new anchorage because I was bored. Just something different whenever the opportunity arose. With more time on the water comes more variety which leads to experience. I'm now confident in me and the boat to sail in wind up to 33-35 kts (sustained) on the Chesapeake Bay and 6' square wave faces.
A few years ago, when our daughter reached teen years and inevitably began to distance herself from the boat, we started racing again, after 20 years. I did it because we were spending too much time tied pierside. I felt that my night skills were atrophying so I entered overnight races. In 4 years of racing, my sail trim skills have improved, I'm far more sensitive to tactics (which translate to more efficient cruising), and the boat operates much more smoothly. We still suck but I'm pushing myself and that's what it's about. Maybe this is too pedestrian for the hard core cruisers, but they can eat my varnish.
Next year is Down the Bay Race (135 mi) and soon the Annapolis-Newport race. Maybe travel to the UK for around the Isle of Wight race (if I can find a boat). Gonna happen.