One springs to mind and also one I've never admitted to...until now. Was on a trip to Germany in 2016 and left early on a Saturday morning to head back to the UK from Neuerburg on my own, leaving the others at the hotel. Leaving the town, there were roadworks so I stopped at the red light and then went on the green as usual. Thing is, the roadworks lane was on the left and when I set off I stayed in that lane and headed down the road totally forgetting where I was until a van came towards me flashing it's lights and beeping it's horn. In a split second I realised I was on the wrong side of the road and moved the bike across to the right so quickly I ended up riding on a grass verge and nearly binned it before pulling over and spending a minute nearly throwing up with the shock. Anyway, got back to Calais in less than 4 hours so the day turned out alright in the end