I have got told afterwards (since I don't remember it, not important information) that my best friend in preschool had walked out and said something like "I'm in love with *my name*". It didn't affect me at all and I had no thought about that it could lead to a relationship, which it also didn't. We was best friends and I just didn't had any thought of an romantic part of it.
I also was totally clueless about what to say when they started talking about crushes in school at like 12 years age. I choosed one guy that was my "crush" but it was more an combination of aesthetic appreciation and that I just thought he was quite nice, but no attraction was a part of it. I was never nervous to talk to him (more then that it's a stranger) and simply didn't care about him if he didn't came too near, then I'd shy away as from everyone. And yes, I thought about choosing a girl instead but no one seemed nice enough and he was the least bad alternative. Kept him a few years, until I realised that I was aroace. I am now crushless and plan to continue that.