This is what I define an easy baby. All of my friends who had babies before me had babies like that and that was my only reference before having DD.
I knew still that babies don't always sleep through and do cry when upset, cold, hungry, sick etc but I never knew what difficult actually meant (to me). Now I do....
A difficult baby to me is one that doesn't feed well (won't take breast milk or formula) or enough of it and is fussy with solids, so is always hungry, one that needs to be aided to sleep for all their sleeps. One that doesn't sleep through the night after 8ish months, one that whinges and fusses and cries and never seems happy (well is happy maybe 10% of the time).
All of the above is/was my DD and I consider her difficult.
Everyone knows that babies do the above things and yes it's common but it doesn't make it any easier.
Nor does my personality, I'm a perfectionist, a control freak and an impatient person, which might in fact make her feel more difficult to me but if another parent had the same baby, a parent who is easy going, laid back, patient, they might not be fussed or phased by a 'difficult baby'.
I want to give DD a sibling so we will be going back a second time. Maybe I'll learn some patience between now and then or maybe we will be lucky and end up with an easy baby.