Firstly, one's profession determines his income level. Given the growing trend of today's people being cynical and money-obsessive, one's income level affact what car he drives, what house he can afford, thus his social status.
Besides, prefession could also determines one's amount of leisure time given the different levels of work load of different professions. For example, a soldier devotes his holidays to safeguard his country's territorial sovereignty,while a primary school teacher could have both summer and winter holidays due to the special school term.
Furthermore, one's profession affects a person's interests and life attitudes gradually. Arists are usually prone to be more sentimental while scientists resort to logic to solve problems most of their time.