Suppose you have resigned your job position and left your working area. After a while, you encounter with a colleague of that job; he / she asks you about the reason you left that e.g. office. (throughout their conversations with you, it's clear that they think you've been fired whereas you were not and you did it by your own will and subsequently you're going to let them know this fact); I was wondering if you could let me know if in this sense the self-made sentence bellow sounds natural or not:
- I left by my own choice.
My second scenario: Imagine a person is competing for a party of a constitution. A friend of him comes to him and asks why he has joined the opposite group which even has lesser financial benefits for him in comparison with the previous party. He says:
- At first it wasn't how much I would earn; the only thing I wanted was joining them; I did it by my own choice.
Does the above sentence work here properly? (Especially the bold parts)