Pregnancy: feeling special, feeling them move, the anticipation of meeting them, the spiritual journey of becoming a mother before even meeting your baby.
Newborn: their soft skin, their tiny perfect bodies, their little noises, the promise and hope they bring.
I don't think people are trying to scare you when they say it's hard by the way...it's just that before you have a baby it's genuinely impossible to imagine all the many thousands of ways your life and priorities will change and because babies also do bring with them plenty of challenges. None of the challenges are even close to being outweighed by the sheer number of amazing parts of being a parent but they do exist.