What they said

I don't think it's presumptuous to be new and say "don't lose me" - but then you should learn the route so you can be independent on training rides, unless you can find compadres who want to hang together.

And with flats... when we're on a beginner's ride then it's a demonstration of how to fix a flat, and we all stick together (usually), or if it's our usual sized group of 6 or 7 and it looks like it's not going to be an ordeal. Otherwise, there's just no point in 30 people standing around or riding around in circles!