Joy Everlasting

What does it mean to have continuous joy?

A joy that is lasting;
that remains unaffected by circumstances
whether positive or negative;

Is joy a response? Or a belief?
Is joy something not out of emotion but cognition?


What is joy? And how does it become lasting?

Over the past couple weeks, people have thanked God for the continuous joy I impart each day.  For some reason, I question what they see. Why? Because I don't feel joyous all the time. In fact, of late I've rarely felt joy. Unless I do have this joy, and I just don't understand that it truly is.

I wonder they mean by this sense of continuous joy I exhibit.
I wonder if I really know what it means to have joy, to be joyous.