I don't know about NYC, but out here on the left coast, the problem with being an owner-tech, and if you treat your customers well, you won't get to retire when the time comes. The phone still rings, and you are still the go to guy when the refer craps out, or the furnace sticks on, or the blower starts making a noise. The majority of my phone calls on the home line, and my cell phone, start with "I know that you're retired, but my (fill in the blank) just stopped working, and I was wondering if you could come take a look at it." If you do like you say, and take care of your customers, you inherit them for life,,,,just not for the time that you are in the biz. Call it a career, but it becomes your life. Only if you are dedicated to your customers, and to the trade.
One way to outthink people is to make them think you think. They'll think you're not really thinking what you're trying to get them to think you think...........