I think Poirot was probably right when he said,
There are not so many round pegs in square holes as one might think. Most people, in spite of what they tell you, choose the occupations that they secretly desire. You will hear a man say who works in an office, “I should like to explore, to rough it in far countries.” But you will find that he likes reading the fiction that deals with that subject, but that he himself prefers the safety and moderate comfort of an office stool.
from Death in the Air