The problem is that most Thai places look at someone who asks for Thai hot extra extra spicy and still judges you from a typical European decent consideration of what really hot is, as opposed to someone who likes food hotter than what most southern Thai people like their food. If I'm going to a Thai place that they don't know me at from several visits, I'll never get a meal as spicy as I'd like after them, because they think I'll complain, even after asking for it.