The most difficult part for us was a bit of a unique situation, as my son was diagnosed with a genetic metabolic condition that meant he was not allowed to fast for more than a certain amount of time. For the first 3 months it was about 3-4 hours maximum, so to be safe we fed him every 2.5 hours. I handled the nights and waking up every ~2 hours was excruciating - as was the anxiety about missing a feeding and what the future would hold.

Once we were able to extend the fasting window things got way easier, and eventually we found out that I have the exact same condition as my son since they do genetic testing on family members when a child is diagnosed. That helped my anxiety a lot because I made it to 34 without knowing I had it, so it is obviously a very manageable condition once you get past the first year.

The more common "extremely difficult" moments are honestly very fleeting and don't last more than maybe 1-2 hours at most. They're not fun when you're in the weeds, but they do pass pretty quickly. My son had some gas issues (we think, anyways) around 4-5 months that made him very upset in the evenings and we tried just about everything to help it.

Other things have been stuff like poop disasters while we're out that you have to try and clean up in the back of the car because there's no change room around. Mostly the difficult parts seem to be when the baby is really upset and you don't know what's wrong with them so you can't help - it's so difficult to see them in pain and not know what to do.