Online dating is an excellent way to be exposed to people you wouldn't otherwise meet.
By asking the right questions, it's a great way to get to know someone before committing to that first date.
If you ask him personal questions requiring a lot of thought, as in "What is the biggest mistake you think most people make in relationships?
" and you don't want to put forth the effort to answer it yourself, don't ask.
At this point, he’s afraid that everything he said in the beginning has led you to believe that you guys are a couple and he starts acting in a way that shows you this is not the case.