Choosing for a career is one of the most important decision that one should make. There a number of factors that might affect this. Here are some:
Introversion vs. Extroversion = Most people are close to the middle of the spectrum and will be most happy in a career that balances time alone with social interaction.
Resources available = you can only readily use what you have in the moment so choosing where to go should be done wisely
Family = oftentimes, it is the family you are with that influences you what do you want to be and what you want to do
Environment= when you adapted fully to a certain environment you tend to choose that over anything else so it influences your decision