Until September, I was teaching A-level at 2 schools in the UK, and had been since 2002. Over the last 3-4 years, the ability of students to apply themselves and concentrate (independent of their ability) seemed to drop away completely. Obviously purely anecdotal, but my teaching experience became much worse in that time period; I'm glad to not be doing it any more, which is sad because it's something I actually love doing when it goes well.