I like to say that I'm the kind of person who's willing to try anything one - twice, just in case the first experience was an anomaly - before saying "I don't like it".
For me, the one sushi, uni, fell into this camp. Uni had always been one of those things that was usefully primarily as a dare or as an initiation rite. In the DC area, the uni that is served is generally disgusting. Eating it is an experience akin to trying to eat an old, dirty and moldy kitchen sponge. I'd long ago given up on it as being fit for human consumption.
A few years ago, while on a business trip to Chicago, I discovered this wasn't exactly the case. I'd been invited to dinner by friends of my wife, Donna (who I'd brought along on this business trip). They took us to this great sushi place in Shaumburg, IL (happened to be about a 2mi. drive from our hotel - how fortuitous!). I'd ordered the omakase sushi menu. I'd asked that they not include uni in my order, given my prior experiences of it it. However, when my plate came out, there sat a sample of it on my plate. Crap. Well, it was paid for and I'm too cheap a bastard to just waste things, generally. Besides: everything I'd sampled, thus far, had been exceedingly good, so, I gave it a shot. Instead of being nasty and unpleasant, it was an interestingly complex experience. It was kind of like eating slightly-squishy sweetened sea-water (and, yes, I know that doesn't sound good, in the traditional sense, but it was rather an *interesting* experience - and, for me, "interesting" often trumps the whole good/bad thing).
With this experience in mind, I modified my stance on uni. I was back to being willing to try it, but only from places whose sushi I *really* trusted and only when it was explicitly recommended by a sushi chef I trusted.
Today, the uni was recommended by the guy at our regular sushi place. So, I figured, "why the hell not." Now, it wasn't as good as what I'd gotten at the place in Shaumburg, but it also wasn't bad. I dunno that I'd order it again, but, if it was put in front of me, I wouldn't automatically pass, either.