"The other day while touching myself I thought of something that surprised me and I came so fast, I would never do that in real life though"
This is a thing I have heard a few times over the years. It is completely normal to think about doing things that feel like they might be below our standards, moral, or comfort zone or that feel wrong in some way and becoming very aroused by the idea.
This is the perfect way to introduce the term kink. Kink is when you are aroused by something that seems outside of what you deem normal. Which is funny because it is completely normal to experience arousal from these things. For more on Kink check out this post.
We can openly explore ideas without fear if we recognize that just because we think about them doesn't necessarily mean we need to physically experience them.
You may find that through thinking about these things you might want to try experiencing them and that is okay too.
Allow a judgment free zone when exploring arousal, and if exploring these things with a partner be sure to allow them to explore these things too.