That is how it went for my sons as well. My older boy (Dominic) has been obsessed with trains from 2 years on. It has turned into a hobby for all of us. Dominic, though a little more camera shy, was the brains behind this layout. The height (2ft), the reach distance (less than 2 ft in case they come off), and the number of independant lines (two loops, a railyard, and a factory spur) were all his specifications. We used Atlas software to lay it out, I did the computer operating, but he guided me based on what he wanted. I was never into model railroads, but now that we have done this I think it is pretty cool.
Nice video Gino.
My guys turned three two weeks ago. They're now enrolled in gymnastics and Tai Kwan Do courtesy Grandma. They got a big Thomas table and roundhouse set and more trains. They're parking the toy cars side by side like a parking lot and trains always lined up on the track. Realism slowly creeping into the fun. A dancing Wall-E toy MUST be replaced atop the roundhouse at night and Sir Topham Hat MUST be brought to all derailments to supervise the cleanup.
I've got a five year old that started on the Thomas stuff about age two. This has turned into all things train related, including watching real trains. A five year old railfan. He's been in the cab of a couple preserved steamers around here (N.E. Oh.) and remembers every location. Can't remember where he put his socks, but can recite the name of every railroad museum and display we've been to including what we saw there. Two weeks ago we were all driving down the road when he pipes up from the backseat that we should turn now, because we "needed" to see the train again. We'd stopped in behind and old rail station converted to a hardware store that has three engines behind it. A year and a half ago. Of course he assigns them names loosely based on what they resemble from the Thomas series.