I agree, I didn't read stuff like that when I was 11ish either. I grew up in a similar rural/semi-rural environment to those kids, and Terry I think, where you spend most of your time climbing trees, building dens, digging holes, fishing in streams and rescuing half-dead birds et cetera. Your whole life is pretty much filled with these occupations and being intellectual hardly ever gets a look in. Perhaps for short periods when relaxing in a newly constructed bunker.

I think Terry and Neil have merely expanded on this life-style and parodied a Famous Five/Swallows and Amazons-type scenario.