As a lefty I've always held my playing cards in my left hand and fanned them out left to right, as that feels most natural. I mean right handed people hold them in their right and fa them out right to left. It wasn't until I was 25 that I realized that the cards are "right handed." As when right handed people hold them, they can see the card suit and number housed in the top left corner of the card. I'd never realized until then that was why cards have those in the corners, so you can see them when you hold them the right handed way. My wife's grandmother tried to tell me I was holding my cards incorrectly because I couldn't see the cards when fanning them out. Any way she tried to fix it, it felt unnatural to hold.