If I may add to the list of "formative" childhood experiences recalled by other Members ... for me the Philips Electronic Engineer Kit has to be in the Top 10
If only because I probably thought you could build a radio transmitter that could talk to military aircraft (see box lid artwork).
Germanium Transistors Type AC126 ... High Tech stuff back then ... and expensive to replace with just pocket money if you got the polarity wrong
Did anyone else have one along with the "sister" Philips Mechanical Engineer Kit ... Learnt a lot
