I, like most people my age, started eating sushi in high school, as part of a little Otaku streak. I just kind of picked it up, dunked in soy sauce, and avoided wasabi/horseradish whenever I could.
Thankfully, I don't do that anymore.
For those of you who still do, here's a great instructional video produced by Vice's food imprint, Munchies, featuring Naomichi Yasuda, one of the best sushi chefs in the world (formerly of New York, you might've seen him on Anthony Bourdain's Tokyo episode of Parts Unknown).
Video aside, eat your food however you enjoy it most. Yes, I dip my sushi fish-side down, but I'm still eating unfortunate amounts every time I go.
And now for your enjoyment, a bonus video, the "Japanese tradition":