I'm left-handed too, so I'm intrigued by your note taking. So you flip through notebooks 'backwards'? How does that help with any of the problems left-handed people have with writing (eg smudges)?
It helps in that I don't have the metallic ring spine digging into my hand (I only write on the recto of the pages. I guess I could write from left to right and write on the verso, but that feels weirder). So this is what my notebook looks like:
http://i.imgur.com/SSc29KLl.jpg the page flipped over to the right being the previous page, and the page under the one visibly written on being the next page.
Sadly, I still have to be careful when I write, otherwise it is a smudge fest (especially with a fountain pen; fortunately, I had a few grade school teachers who taught me how to write with my hand positioned in a way that minimizes smudges)
Update: Just came back from Muji with quite a bit of stationery!
Your argument about which kind of writing instrument is popular in which country is very interesting, but you seem to think Moleskine is a US company? In fact they're from Italy. Not sure if that changes your reasoning, but it might be worth mentioning since you seem to not be aware of it.
Hah, TIL. Well, the fact remains that Moleskine paper fares poorly with fountain pens.
Also Muji is a Japanese brand - the paper works really well with fountain pens, which are common there. Moleskine paper does not fare as well (as fountain pens are rare in the US). Being French (one of the few remaining fountain pen heavy cultures, with Japan and Germany), I still write daily with a fountain pen and deeply enjoy it.
Oh and also I'm left handed, and thus write in my notebooks from last to first page (in western order) - since Muji is a Japanese brand, the notebooks are designed to be used in that way. That's a little detail, but I'm a little obsessive :-)