Like say I can take it easier with my Uni students who almost always 'take care of themselves' and will improve
their English even if I slack and have fun classes. The lazy kids (some not too bright) and little buttheads AKA the 'unhealthy ones' who don't take care of themselves - THOSE are the ones I need to work on, pay attention to and make sure I keep on them or else its very very noticable!

Accurately evaluating a student's ability and effort is always problematic; in an EFL environment it is nearly impossible, even if the FT is fluent in the students' native language and is familiar with their culture.

Arrogance and prejudice are always offensive; in a teacher they are a disaster for his students.

Writing students should be taught that a spelling error that occurs in the final word of a run-on sentence and that is followed by a superfluous exclamation point is 'very very' noticeable.