In my childhood
I got into toy trains when I was a kid. My dad had an old Lionel "O" scale set that was piled in a box, but I couldn't play with. Eventually they bought me a pretty decent "HO" set. I loved that thing. I always played with it and saved my money up to buy more trains, track, accessories, etc. Of course being pretty young in a poor household meant that I did more dreaming than purchasing. Eventually I grew out of it. When I move out and wanted to take my trains with me I found out my Mom had given them all away. As an adult I couldn't imagine myself playing with these things ever again. My son is almost 12 and I know he might have some initial interest, but I doubt they would keep his interests for more than a hour (there's just too much competition from video games and legos).