...you go for the ASS Cancel button... and miss!
I'll set the scene for you - I'm driving along the A272 and as I come to the traffic lights where it joins the A24 dual carriageway, the traffic lights (C) happen to be green. I pull across the junction and spy a very nice E92 Coupe waiting at the lights (B). No problem, my lights (A) will change to green about a second or two before the E92's lights (B) and with 10-20yds head start I'll be gone before anyone knows it, just need to prod the ASS Cancel button for a quick getaway as I roll up to the lights.
ONLY I MISS THE CANCEL BUTTON AND HIT THE START/STOP BUTTON INSTEAD!!
The car was actually still rolling forward at this point, albeit very slowly at which point the engine stops, the autobox dutifully selects Neutral and the car comes to an abrupt halt!! In the few seconds it took me to realise my mistake and get the engine started and in gear, this Mineral Grey Coupe cruises past me, probably thinking to himself "Wonder why he's still sitting there??".