I worked as a teacher. Teaching is not always enjoyable for me but it makes me glad especially when I received cards from my ex-students to tell me that they are doing well after graduating from my school and they appreciated what I had done for them. Happiness may not always be there but there are little things like these can keep us going in life.
!tip
Well, yes, I have read somewhere that-
Be the reason for someone's smile, you will find joy there...