I like Darwin. He seems to have been a diligent, honest thinker.
I don't suppose he was the only exponent of the evolution thing, but it was from his work that I got the idea, and it makes sense to me. In fact it more than makes sense, I don't see how evolution could be a false idea. If you've got something that reproduces itself, with a bit of random mutation in the mix, and then dies, then the mutations that are fittest for survival will survive best and you'll end up with a preponderance of them.
I also like his idea that we're part of the evolution of life, a member of the family rather than something qualitatively different from it. Again, I don't see how that could be wrong.
So he probably changed my life by showing me those ideas about what we are and how life ticks. It's also reassuring to see that although he was an Aspie, he managed to throw some light on the mystery of what we are, light that a lot of people have found useful.