It's perfectly normal to be a little squeamish of bodily fluids and functions when you don't have children. Very few people would choose to watch someone else go to the toilet, and you certainly wouldn't offer assistance with basic hygiene functions.
Somehow, all of that reluctance magically goes out of the way when you've had a child. Your child could projectile vomit all over your face and hands, and you'd just calmly shrug and wash it off. The most disgusting of bodily functions become completely routine. You think nothing of picking their nose for them in public. This seems to happen automatically. Maybe it's better that way; it means you don't have to think about what you're doing too much. By the time you've changed your hundredth diaper, you've seen it all, and it's officially no longer possible to shock you.