You think that this is what kids are like. They sit there, they walk a little, they giggle on the playground, they look cute as all get out, etc.
Then you have kids and you know.
You know.
Those kids sitting there in the booth sipping on their milk quietly while mom and dad happily eat their lunch? Those are the top 5% most calm kids out there. The other 95% of kids are with their adults screaming and throwing fits and covered in who knows what.
Life lied to you. It did it directly to your face, unashamed. The bias is real.