I really don't like 'dive in' sessions because, um... I just can't!

I absolutely hate the actual business of judging whether someone else is about to start and perhaps getting it wrong and both starting at once. So, usually, I just don't bother and that means I never enjoy the session very much.

I much prefer a singaround / tune-around where everyone gets a turn; at these I will usually get several turns whereas at a 'dive-in' I'm lucky if I can pluck up the courage to play even once!

I think it's that 'diving in' makes me feel pushy - a feeling I really don't like. Perhaps, as a child, I was told too often to sit quietly and not interrupt the grown-ups :-)

Horses for courses as people have said.