At best I might call myself aspiring rationalist (like Kenny elsewhere in this thread suggested) because I fail very often as rationalist.

As for experiences that have led me to try to be more rational...

I read Sophie's world[1] when I was about 14 years old and that inspired me to think I how I could tell if I wasn't actually living in a 'real world'.

I was curious about different beliefs humans have in my teens and if there might be truth to some of those beliefs (and which ones). After finding local christianity unsatisfying for several reasons and looking for alternatives I ended up reading a spell on internet forum that had a strong point about what works [2]

After enrolling to study psychology I read and completed excercises in SICP[3] for various reasons. It was very inspiring to read and especially 4. chapter (Metalinguistic abstraction) was very enlightening. I think that both programming and learning psychology both increased my yearning for being more rational.

There could be other events too.

1. http://en.wikipedia.org/wiki/Sophie's_World
2. http://www.chaosmatrix.org/library/chaos/rites/buff.html
3. http://mitpress.mit.edu/sicp/