So, one amusing (to me) pasttime is writing people's obvious lies into head-canon, and then enjoying the world I live in as a result. So in this case, I like to imagine a much younger Miniman having actually found a giant, slumbering dragon somewhere in the Northern Territories, having been adopted by the local culture as their golden child, having trained (via montage, of course) to stand toe-to-talon with this dragon, and having finally slain the beast.
And now nobody on the internet believes him.