No matter how old you are, it’s always fun (in my opinion) to make ‘toys’. However, if you’re the type that needs an ‘excuse’ to play around with stuff, then you should simply skip the Science Toys site. It has a variety of ‘experiments’/toys from various areas of science.

There is even something about playing with electronic fish - something like an electric eel, only not quite as dangerous.

I have an urge to try making the ‘3 penny radio‘… but I’d need a few parts first. Hm.