This is a concept that took me a long time to accept. Having experienced true depression in my life, the idea of being able to choose joy or choose to be happy seemed impossible to me. It is something that I still struggle with. Sometimes it is hard to be naturally happy and on those days it has to be conscious choice.
I have a little sign next to my desk that I made my freshman year of college that says, “Today I am choosing to be happy.” Somehow this little canvas sign has followed me for the last four years, through several moves, all the way to where I am now. During that time I was really struggling with my depression and I had to make the conscious decision to be happy or at least to find things to have joy in. At the time, like now, I had just moved to a new place and had to make new friends and have new experiences. Some days it is harder to choose to be happy than it is on others. I believe that it is okay to be sad sometimes and it is okay to not be okay all of the time, but it is not healthy to be sad or depressed all of the time.
I can say from experience, it feels so good to finally feel okay and even better to feel good, after not being okay for long time. Sometimes you have to choose joy or choose to be happy for days, weeks, months or even years before you really feel it.