Infinity isn't hard to understand, yet try to fit it inside any theory and people will start to get headaches because they ask the wrong questions imho hehehe.
The start or end of things is quite irrelevant when something goes on for infinity and when what you really want to know is about that infinity.
I know there's one flaw in this reasoning, because things that are infinite can have a start and simply go on forever after that, however as for the beginning of things and the big bang, what exactly do we know about before the Big Bang? So, that does mean that we can't say for sure that it's the start,
Cheers