a difficult teen and it's a whole notha ball game. Instead of just feeling hen pecked or sleep deprived, you now worry that they'll become drug addicts or worse. Lots of fighting, etc. The worry is more all-consuming and pretty terrible.
I know someone whose kids were okay until late 20s/early 30s when their lives kinda fell apart. They look at our teen troubles like they're nothing. A lot of it is perspective I guess.