Bah, I was approaching a medium-aged woman on a bike and was wrestling with the eternal question, to ding or not to ding.. I judged that she appeared to know what she was doing and was making progress in a nice straight line, very clearly on one side of the path so I wouldn't ding my bell in case it jolted her into swerving.
Wrong! Just about to nip past and she inexplicably wobbles right over to the other side of the path. Luckily I had eased off as I approached her to have a drink. Still had to slam on fairly hard and wet rims didn't help so it was close, but she was completely unaware how close we had come to saying hello to the ground.
As the overtaker its my responsibility not to knock her off, I admit, but still, people riding unpredictably drives me crackers, especially on a busy path. I've been spoiled with lots of good riding recently so got complacent, I must make my presence known sooner, it annoys me how easily preventable it was and I consider myself quite good at observation and planning. ARRRRR!