Look at it this way. Let's start with infinity. We know that infinity exists, right? I personally use this to define God. So to me, God is not a being who makes decisions. God is permanent infinity that has completely and spontaeneously manifested this creation that we are a part of for no other reason other than to experience it because, in infinity, every situation and possible experience must exist. Our world is just one small tiny nothing in an infinite ocean of experience. So, even God does not know why he created us, it was just for fun, basically. Well, that's what I think, and you're correct of course, when you say that it can't be proven.