I don't remember where I heard it but someone recently said "It is easier to act your way into a feeling, than to feel your way into acting."
I think this is quite profound.
On a practical level maybe there is something that you know you should do for your spouse, child, neighbor, and yet you just don't feel like it. If you make a choice to do whatever the action is, often times you will start to feel positive about them.
If you just wait for a feeling to hit you before you do anything you may wait a long time and miss out on the joy God has for you.
Reminds me of God's conversation with Cain in Genesis 4:6-7, "Then the LORD said to Cain, 'Why are you angry? Why is your face downcast? If you do what is right, will you not be accepted? But if you do not do what is right, sin is crouching at your door; it desires to have you, but you must master it.'"