a quest for knowledge is justification in and of itself. It needs no further motive than to just know. It may have struck him odd or he may have wanted to make a point. Either way, we can either relay our opinions on the subject or ignore it. To castigate someone just because they want some information is not conducive to an open conversation. He has indicated that there exists no other motive than mere knowledge, so I suggest we leave it at that.
As for his quip about arsonists, I thought it was genuinely funny. It is not his fault if you did not see the humour in it. I have been labled "weird" throughout my life as I see things from a somewhat skewed perspective. The need to pigeon hole people like that is counter productive and rather revealing in and of itself.
BTW, I like my humour skewed over an open fire with just a hint of oregano.