[Seeker]

As someone who lived in the US for 20+ years it seems an odd question. Most of the time when I get on/off my bike I'm at home/at a petrol station/in a shopping centre car park/at work. Speaking as a short person, the road camber helped getting on/off when I was on the right (hand) side of the road - the bike leaned less and required less effort to pull it to vertical.
Here in the UK, it makes me nervous if I stop on a steep camber, the side stand is down but the bike seems to lean...and lean before the stand touches the ground.

Perhaps a better question would be - which foot do you put down first? It would make sense in the UK (with my vertically challenged body) to put my right foot down first but here and in the US I put my left foot down first.

I used to ride horses, too, and I'm trying to visualise mounting from the other side (and failing). Does it affect left handed people more?

Edit: from Horse and Rider. "Mounting from the left is just tradition. Soldiers would mount up on their horses left sides so that their swords, anchored over their left legs, wouldn't harm their horses' backs. But you're trail riding, not heading into battle. Make sure your horse is comfortable with you mounting and dismounting on either side."