Why do babies cry so much?
It’s not necessarily that they’re grumpy but it’s the only way they know how to tell you that they need something. But you’re right, sometimes all their needs have been met and they still cry. Some babies will do this because of gas and the pain it causes them. Some babies, after a long day of stimulation will do it as a form of release, much the same as you would come home from a long day of work and vent. They eventually cry less and less as they get older and become able to express their emotions in other ways.