> That said, for most people the purpose of school is to prepare them to be able to support themselves and their families, and it sounds like he's basically able to do that now.

The real question you have to ask is whether you can do both (impractical and practical) -- if you can do both, then it is clearly better than doing one.

You may not realize it now, but a lot of things that seem impractical can become very useful (or at the very least, fascinating) when provided with the right context. For example, if you ever want to learn about how your computer works on the inside, knowing basic physics will give you better perspective on what's happening. More obscure stuff like Quantum Tunneling starts appearing in technologies like NAND flash memory -- it's not necessarily practical to know all that, but I'm very happy that I know it.