Mine is my railroad empire. A long time ago, in 1984, the D&J Railroad was born in N. Stafford, VA. It was a small railroad and didn't even have an industry. Trains would move from one end of the simple switching yard to the other, sorting cars that would go nowhere. A small boy took his turn in running the Trainmaster and learned the principles of coupling cars without slamming them. He grew to understand how to lay track and solder wires. Soon it came time to name this railroad and he suggested, "How about the Dad and Jon Railroad". I thought, how cool that he had the cognitive reasoning to come up with a name like that. The name was approved and the first locomotive and revenue box car was painted with the logo. The significance of the road number was, 2 (my wife and I) 3 (my three kids) and 5 (the total of the family).
The railroad expanded and became a dogbone configuration then later expanded again another 20' around the basement. The rolling stock roster grew along with the list of leased motive power of the Southern Pacific, Union Pacific and Santa Fe lines. Industries sprung up around the layout and business was good.
Finally, one day when my son was in his Junior year in high school he stopped me in the kitchen upstairs, and with a very sincere look in his eyes said, "Dad, trains aren't cool anymore", then asked for the car keys. I was stunned. My railroad buddy of the past 10 years was walking away from our interest. It was emotional for me to suddenly hear that decision, but before I gave him the keys I summed up the composure in spite of what he just told me and said, "if you're going north, stop by the hobby shop and pick up a couple of #8 turnouts for the oil industry I was going to install". "Yeah, sure dad."