Edit: this is not a generic smugness, but a specific one. Still makes me smile when I think about it, though, even now. Possibly 'cos I used to sit in gridlock in that village in the car - gridlock often caused by people like the one I describe below who couldn't just wait for a few seconds.
I did once go a different way to work (needed to drop stuff off at the in-laws), which took me through a village which is often gridlocked* in the morning. As it was that particular day.
I was kind of going round the side of the gridlock, and then across it down a road which is no-through to motor vehicles but links to a bridleway. The gridlock was starting to clear and there was a WVM (rather sensibly) waiting for the last few cars to come the other way to complete that clearing process so he could continue on his way. This seemed to cause considerable annoyance to the woman behind him: she was tooting and telling him to "get an effin move on", gesticulating and so forth. (I suspect this may have had a bearing on his decision to wait for the oncoming traffic
).
She was stopped across the road I wanted to go down, so rather than try to squeeze round behind her on the bike, I pulled up to the left, got off and walked across the road between her and WVM. She was still hollering at him, so I joined in along the lines of, "yeah, go up there when you can't go anywhere and block the road then you can all sit here all day".
That earnt me an "and you can effin shut up as well", so I got back on the bike, gave a cheery smile and wave and went off down the side road.
* there's a row of parked cars, then a gap, then more parked cars, repeat. Due to the curve of the road, you can't see if anything's coming the other way. You often get two rows of cars meeting head-on alongside the parked cars and nobody can go back 'cos of all the cars behind them.