Deserters fell from Jesus' ranks until only twelve remained, and one of them stayed with Jesus for all the wrong reasons. You have the words of eternal life. Or even more popular today is the thought that we should resolve to change ourselves or our circumstances to become happier. Jesus had a different formula for joy. He was talking about becoming fruitful disciples by abiding in Him as branches abide on a vine.
Some people can walk through a forest and can identify most of the trees by their bark and leaves.
I can't do that. But, if I see an apple hanging on a tree, I know that I'm looking at an apple tree. Jesus made it clear that fruitfulness and joy in the Christian life go together. The source of this life is our Lord and Christ. Fruit is the product of what God does in and through us, and experiencing ourselves as channels through which the love and grace and compassion of Jesus flows is a source of tremendous joy.