Our level of wellbeing does not change much, with each event, even a catastrophic one, impacting us for a length of time, say a year or two, and then becoming normal to our minds, returning us to our previous levels of wellbeing.
People with high self-esteem are more ambitious and confident to be able to rise in the ranks, regardless of the actual talent.
Family history plays an important factor, with successful parents having ambitious children.
An extrovert personality contributes to the ambitiousness of a person, and many countries specifically look at the personality of a candidate to suit their requirements, looking at the long-term aspects.
Ambition can be individual or collective, and while collective ambition is great if one is able to channelize the same, individual ambition at the expense of the organization as a whole can be counterproductive.