Tahnks to Internet Arguments, I'm looking over the Harry Potter books again for the first time in a long time.
One thing I caught was that the Weasley Family, after hearing "Excuse me..." immediately admits the existence of Hogwarts to a total stranger. Now, assuming that this wasn't an evil conspiracy to bind Harry to the Light for the Greater Good, it means that wizards are very, very daft.
Let's assume this isn't unusual. That every once in a while, some idiot wizard accidentally leaks the secret to some random passerby. At least some of them are going to be curious about this "Hogwarts" place, and play along long enough to get on to the train.
There are no tickets, so no one catches on until the Sorting Ceremony at the earliest. Given that peopel can apparently pass classes with a mismatched and even broken wand, it wouldn't surprise me oif a few intelligent muggles managed to pass classes enough to get through the first few years without incident, especially if they take non casting classes, like Care of Magical Creatures, Divination, Herbology, Hostory of Magic, and the like. Not much of a caster, but I'll be damned if they don't know their theory!
Not even much of a stretch, given that a DADA teacher can't even handle pixies, a 2nd year threat.
Just like the idea that due to wizard idiocy, one or two muggles attend Hogwarts every year with none of them the wiser. For those in control, smuggling a kid into Hogwarts might be a necessity, if their child is planned to rule Britain as Prime Minister in the future!
Thoughts?