I agree with the advice that stepping out of your comfort zone is necessary for personal development. But I also agree that rest (getting back into the comfort zone) is absolutely necessary. Some of my best life experiences were going out of my comfort zone for an hour or so then returning more enlightened. Some of my worst were going out of it for an entire day or week without any time to rest and reflect.

That being said, your points are valid depending on what you are used to. The social event where you know no one is a natural step after you learn to mingle with strangers alongside friends; if you haven't done that at least, the event will probably suck.