When I used to work part time in a
training centre, I used to have students contacting me to ask what my teaching schedule
was so that they could book my classes.

There is nothing narcissistic about it either. Being popular with your students makes you
feel like you are doing something useful.

There is nothing arrogant about that. If its 'boasting' then its boasting about giving your attention and to others, doing your best for other people and helping make other people improve.

and that is a good thing!