Pretty simple question - just wondering what your thoughts were...
My answer is yes. However, it is not as simple as "I am now happy," instead, it takes effort, and here is one way that I have had success at choosing to be happy.
The practice of meditation. This is being in a quiet place, and simply being silent. Your mind, thoughts, body, everything silent. Once you can stop the flow of all your thoughts(it may take practice and time), then you can start just being a witness to all surrounding things, without interpretation. Since our thoughts (both conscious and subconscious ) are the culprit of making us feel displeased, when you stop all thoughts in meditation, you can then learn to start letting new thoughts in, and change the direction of the flow to what you want. Its sort of like hitting the reset button on a computer.
It's about what is; not what it might be or could be.
This has been working for me. The less I think, the less emotion fills me up. And I can now choose which new thoughts to let in.