i can't (nor want to) speak to the concept of "movements", but as for the question of young anarchists, that's a good one. ba@ linked to a related question on this site, which has some decent discussion on the topic.
when i was about 15, my best friend was a marxist, and turned me on to "marx for beginners", which planted the seeds of anti-capitalism that ultimately led to my anarchistic perspective. 5 years later, in 1980, that same friend voted for ronald reagan, and has been a card-carrying republican ever since.
back when i was closer to @ scenesville (bay area, eugene), i was often around young anarchists. few and far between were the ones i met that seemed to have a deep enough, personal enough critique to possibly last past that few years of youthful, rebellious, anti-establishment energy. unfortunately, that bears out more often that i wish it did.
i think the answer by metalist on that question ba@ linked to (
http://anarchy101.org/8908/average-time-someone-identifying-anarchist-anarchist-ideas) speaks somewhat to what i am getting at here. simply put: (youthful) idealism vs (a more grounded) self-interest. i am not describing it as a dichotomy, just contrasting.
[quick edit for clarity]