This has come up from time to time in other threads so this is something of a repeat on my part. But for me there are three main reasons that I like boating.
One is running the boat. As I've described in other posts, I really enjoy simply running the boat, which is a big reason why we will never have a single engine boat. I like operating machines and the more complex they are and the more options one has in their operation the better I like it.
Two is being out on the water for more or less the same reasons John posted above. Plus up here the life in the water is amazing. From jellyfish to Orcas and whales, cormorants to eagles, seals to otters, there is always something going on around us. I also really enjoy the challenge of learning to deal with the water up here. The strong currents, major big tidal ranges, rapids, narrow passes, rocks, and reefs. Not a big fan of wind, however, but we deal with it and when we deal with it successfully it's a rewarding feeling.
Three is working on the boat, particularly the woodwork. My knowledge of working with metal is pretty much non-existent, and I am very close to the bottom of the learning curve with fiberglass and gelcoat. But wood I understand and while I am no cabinet maker I am pretty good at finishing or refinishing wood. The big frustration now is time. I don't have nearly as much as I need to do brightwork properly. Hence all the covers on our boat to keep the weather at bay.
Last or not even on my list is the destination. Something like a nice anchorage, preferably with no one else there is great, no question. But marinas, harbors, etc. I have little interest in beyond the sometimes challenge of getting in and out of them.
The social aspect of boating is a total non-starter with us. We have a very small number of friends in the US and in Europe who we will take out on the boat with us. Currently there is only one boat-owning couple we really enjoy going out with. But talking boats or anything else with people who wander by on the dock or who want to meet up somewhere for coffee and so forth is not something we--- particularly not me--- encourage. I deal with people all over the world all day in my job. The absolute last thing I want to do on our boat is deal with more people.