The students would like to know there are adults who actually enjoy their work and think it worthwhile. There is nothing compelling you to be in that classroom other than your genuine enthusasium to share your knowledge with the students. Most students appreciate this fact. Use it to your advantage. The children know that you are giving of your time.
Children are eager to learn about how adults make money.
Many don't know what their parents do for a living. If you think your work is fun, tell the children enthusastically. Students seldom think that anyone can have fun working.