Your identity creates you. And you choose your identity. Yes, your childhood, your parent's view of you, the way others have treated you, who you compare yourself with, all have had a part in creating your identity. But it's only because now in the present you have decided to keep the identity you have been influenced to have. And if you haven't made a conscious decision how to view your identity, you are still making a decision, albeit a passive one. You might already view yourself as a happy, joyous person. If so, great. If that's not yet your picture of yourself, it makes sense to start viewing yourself this way now. All you need is one moment of happiness or joy to consider yourself as one.
(From Rabbi Pliskin's "Happiness",p.95)