Get excited and get happy for no reason. Do not make it where you need a reason or something has to happen for you to be excited. For you to be happy, you have to practice being happy. If you want to get better at anything then you have to practice. You must build the pathways in your brain and body. The more you practice the easier it will be to get there. The more you strengthen your synapses firing the more you will feel this pleasure. Whatever you are feeling you will feel more so why not feel happy.