Airfix kits were a very important part of my youth. I built many Airfix aircraft, ships, cars, and of course the Railway rolling stock and buildings*. With Meccano construction outfits and Triang Trains it occupied most of my spare time, and taught me how to put things together and make them work.
*Kitmaster railway kits too came along at the same time and added to my delight.
Of course there are modern equivalents (almost) with Parkside rolling stock kits now marketted by Peco, and Slaters too. I have moved up to building wagons in 7mm scale (eyesight isn't what it used to be) but I do have a bit more pocket money nowadays.