When i was younger i was scared of going on the Corkscrew at Alton Towers but eventually went on and loved it... Same happened again when i think i was about 10, crying my eyes out having a domestic in the middle of Forbidden Valley with my dad because i didn't want to go on Nemesis because i was too scared, i eventually gave in, and with lots of napkins from the McDonalds there stashed in my shoes under my heels, i reluctantly went on it, and well i needn't have worried as i absolutely loved it, and is probably the reason why it is still my favourite ride now, although it is undeniably an amazing ride regardless of nostalgia. The reasoning behind my dad trying to get me to go on Nemesis (without telling me at the time), was because the year after, 2005, for my 11th birthday, off we went to Florida for two weeks and literally had the busiest and best holiday ever! Still have yet to return to America though!!
EDIT 1
Back from when i was younger i had a fear of rides crashing etc... and I remember running to Sheikrah at Busch Gardens literally a couple of days after it officially opened, and the queue line was still being painted and i started panicking and rather than being on the first train of the day, I made my dad wait for people to go past us just because i didn't want to be on the first train in case it crashed, guess i didn't realise they done tests etc. back then, but i still get that sort of paranoia (which is more related to rides breaking down as I know they are really safe now, I just get claustrophobic if I'm stopped too long, or just being on Colossus at Thorpe Park) in the back of my mind today which i usually blank out now.
I actually chickened out due to being scared of a ride crashing... which was X No Way Out at Thorpe Park, as i used to hate the bits where it would stop and roll you up and down the inclined break sections, and constantly thought it wouldn't stop you and would roll back down into the previous bit of track into another train, so on quite a few occasions refused to ride on that basis! Am i glad that they turned it into X, forwards and no stopping, i actually love it!
EDIT 2
Having actually read through this topic... I've also point blank refused to ride Furius Baco a couple of times while EthC went on it and he probably regretted it - i literally could not be dealing with the headache for the rest of the day, and unless you happen to be in a particular seat on a particular train at a certain time of day lol..