The bends

[Poacher]

Generally happier and more confident on left-hand bends in the UK. I suspect it's largely to do with the camber of the road, and the reduced likelihood of a head-on collision (since I'd tend to ride towards the centre of the road, or even onto the RH side on a narrow road, on a right-hander). This assumes the bends are not particularly tight, which would affect the line taken, so as to reduce the tightness in either case.
Sorry if this makes little sense - I'm also becoming more tight by the minute.

 

[Fab Foodie]

Most people find going left preferable. Supermarkets for example, take advantage of this weirdness by generally having the entrance on the right hand side of the building as we feel more comfortable entering the space and knowing we need to go left!
Strange but true ....