I'm not sure that you can "prove" the hypothesis that change uplifts a man's life, but I'm sure a lot of people would testify to the fact that making changes can be the catalyst to feeling about better about themselves.
The saying "a change is as good as a rest" adds weight to this theory. Often people think they are tired and need a rest, or a holiday, when in fact they may need to look at the reasons why they feel like this, and find ways to make changes.
Leaving a job that you are unhappy in, ending a relationship that is destructive, or making changes to an unhealthy lifestyle can all have dramatic positive effects on mood.
These are all quite big life changes though, sometimes small things can have equally powerful results. For example, walking to work instead of driving. The exercise may give you more energy, lead to weight loss and an increase in endorphins and serotonin.
Not having to sit in traffic and get frustrated, being outside in the open air... All these factors may play a role in making you feel better, just from one small act.
