That attitude you described sounds pretty much like late teens/early 20s, I remember going through that phase XD and currently eldest is going through it aaaaaaaahhhhhhhhhh x_x
Yeah! That was exactly the age. Good luck with your child, I can't imagine how it must be like to deal with someone going through that as a parent.
Painful. Especially when they are very definitely smart enough to know better but don't have the life experience to actually know better, and you can't tell them anything because you're old and the world that you grew up in is somehow totally and completely different to the one they're growing up in now therefore absolutely everything you know is totally and completely irrelevant and they know better than you ever will XD
Thanks for the luck, probably need it, got two more to go after this one aaahhh XD
Ahhh yes, I remember when I too thought that I knew better than anyone older than me, hahahaha. Fortunately, the thrill of "being right" passed soon enough for me to wise up. May your kids learn that lesson even faster than I did!