Was the mission for your first airplane what you thought it was going to be before you bought it? What do you know now about how you actually use the airplane vs. the way you thought you would?
The Mooney is my first plane, but I rented for 12 years and have participated in forums for many years, gone to fly ins and talked to owners quite a bit, so there hasn't been too many surprises because, well, I knew to expect expensive surprises from time to time. Expect the unexpected.
My wife is a double edged sword. On one hand she is very supportive and encourages my flying, but on the other hand she does not care for it one bit herself. This means I fly around by myself a lot which I'm OK with, but it also means I really don't go anywhere far away... yet. I would be perfectly happy with a Lancair Legacy, or some sort of two seat experimental, but strangely, it's my wife that insisted I buy a four seater.
I had envisioned what I do, flights around the patch, local fly ins and hamburger runs, but I had also thought of traveling further on over nights. Doesn't really happen for me. Two reasons, I can't guarantee reliable service (leave Friday and absolutely for sure back on Sunday) and expense. The gas bills are an eye opener. The later is more of an obstacle than I thought it would be.
I could in theory decide to go by myself to Vegas, or Santa Fe, or Sedona, etc, but when I think of the fuel bill it seems a big waste of money for essentially a long distance hamburger run. Fly ins do give me a good reason to go, but there are only 52 weekends and my free ones rarely seem to mesh with others.
Still, I am happy with ownership and enjoying the plane. It's fun to tinker with and upgrade and I really do enjoy my spontaneous afternoon magic carpet rides around Nor Cal. My advice to someone thinking of owning would be-
Think efficiency and fuel economy. The fuel bills really suck.
Buy experimental if you can. It will save you money and headaches.
Do owner assited annuals, get intimate and involved with your plane's maintenance. It could save your life. I know it may have saved mine.
Plan on a hangar. It really helps and it amplifies the owner experience.
If you're not married yet, only marry someone that likes to fly in little airplanes and have a long talk about kids and what that will mean for your flying in the future.
Have lots of money and be willing to part with it. Flying airplanes is silly, stupid expensive.
Think of ownership as an adventure, with lots of pit falls and thrills along the way. Be flexible and prepared for the worst.
Good luck!