I have "left" MN before (although I have never made a formal announcement).
Sometimes you just need a break.
The beauty of an internet site is that unlike a close, but occasionally annoying, friend, you can't bump into MN at the supermarket while you are eyeing up the fruitshoots curious to know "should I try one?" "what does it taste like?" and "will it kill me?". (No I don't do that - or do I?)