Congratulations! Being "free" at last is one of the greatest feelings a person can have, even if in a case like mine it's going from working for someone else to working for myself. It's nice not living by the clock anymore. I long for the time when I can only pick just the projects which interest me, or not work at all. Just make sure to keep busy. I noticed how may dad deteriorated physically and mentally during the 11.5 years he was retired. I'm convinced that some people need the routine of work to stay sharp. Others, like myself, can probably keep themselves occupied for millenia if we lived that long.
You have a great hobby in model railroading. It's one I hope to get back into one day when I have more space and time. Building a dream layout is easily something that can keep you occupied for decades. I've been heavily active on the electronic end of model railroading in the past, so if you need things like passenger car lighting just give me a heads up. I've also made a prototype train control which (once calibrated) displays train speed continuously by measuring the back EMF from the motor. I hope to get it into production one of these days.
I second mubs suggestion of gardening as another hobby. I grew vegetables for many years, but stopped about 15 years ago for various reasons. This year I'm going to try and get back into it. I'm starting some seeds (eggplant, peppers, tomatoes) in a few weeks (courtesy of LED grow lights I'll be making) for transplant once the weather warms up. Nothing like growing your own food, especially in a big city where few do. The taste beats the store bought stuff any day as well.
