The last time I got overtaken, I was fiddling with the rear gear barrel adjuster. It's the first time I've ever been 'surprised' by another cyclist as I usually see any potential threat in my mirror. Needless to say, I soon got back into the zone and re-took the offending cyclist. Oh, and I did once get overtaken by a MB. It was on the cobbles in the town centre, and I was taking it steady as I was on 23mm tyres. And yes, I re-took him like he was standing still when I got back on the tarmac.
Attention to all cyclists in the Doncaster area. Do not attempt to overtake me

.....I will humiliate you.