My child sleeps through the night now, but those memories come back crystal clear the times when my kid wakes up in the middle up the night sick or with a fever

My child sleeps through the night now, but those memories come back crystal clear the times when my kid wakes up in the middle up the night sick or with a fever. I have definitely heard about the sibling thing as well from families I know, but in the opposite direction. First kid is very chill and easy going, parents think they are perfect parents. Second kid is fussy and more difficult and parents realize they weren’t necessarily natural experts at parenting.