For the parents of the mode difficult teens, at what age did they change? For us DD went from being the easiest, calmest kid, to a very very difficult teen beginning of Y10, so right after 14th birthday. It seems this is quite common. Either the 13th or 14th birthday seems to be the most common.
Thankfully we're slowly getting to the other end, but I'm curious if this is something others have also noticed?