My son loves fungi. He reads loads of fungi and mushroom books, the favourite being a handbook to identify them. We see it as a way to enrich his mind and explore the world so we engage with him on this. We go mushroom foraging, not necessarily to gather them to eat, but to photograph and identify. We'll spend an entire weekend doing this but mix it up, like having to cycle somewhere, or explore a new forest, stop at a play ground, etc. We get other people and their kids involved so he can socialise while doing what he loves.

He's converted me. I'm now obsessed too, but not in it as deep as him.