Ch 87:

It seems like Harry is falling prey to the typical mind fallacy in his conviction that it's impossible for anyone who hasn't entered puberty yet to experience romantic attraction.

He can't be an expert on everything, so I wouldn't be particularly surprised by his making what probably feels like a safe assumption, if prepubescent romantic attraction weren't common enough to have a well known colloquial name.

This is a case where human minds vary a lot more than a naive hormone-determinative view might suggest. Simply questioning my own social circle has turned up results from individuals who experienced no romantic or sexual attraction before puberty, to individuals who experienced either or both from early childhood.