When is it time to retire from writing?

Is it when your muse has flittered off to the far reaching corners of the galaxy to have a good time among zeltrons and twi'leks. Or is it when your mind starts to play tricks on you? Is it a certain age you reach?

I don't know, and I've been trying to figure it out. I'm older than most writers, and I've long looked at this as my way to relax. But when frustration becomes associated with relaxation it is time to take a serious look at everything and ask...am I having fun?

I'm use to having stories abandoned, as much as I hate it. I'm use to my ideas for a story not to be someone else's. I'm not use to long periods of. Hmmm what do I write now?

So..when is retirement? And am I ready?