Why do I do it?
I have always been a fan of mixing metaphors, so.....it was the monkey on the back, an involuntary urge. But one thing I have learnt over the years is that we should release the handbrake and allow our gut instinct to take over, let nature take its course. Failure to do so is a step on the road to frustration and perhaps even disaster.
So take up that pencil, brush whatever, gird your loins, then it's up and over into no-man's land and watch out for incoming.