Confidence is everything. The key to a successful career and getting jobs with a possibility of growth is confidence in the interview. The hardest internship to get is the first, and the hardest job to get is the first. The job usually proceeds the internship, so the "first job" in this context means not as a carryout at a grocery story, or as a waiter at a restaurant. This first job where more than minimum effort is required is the most important for your career because it sets up all other opportunities that will arise. Two keys that this first job provides is confidence in further interviews, and experience with management which is important to moving up the employment ladder in later positions.
Confidence in one's abilities is the key to landing later positions. Employers are looking for employees who are confident in the tools they have to offer. The first interview for a job paying more than minimum wage may be a stressful experience, but when hired it is a great confidence-boosting experience. Another aspect of being hired for this first job is that one probably had to beat out other people searching for the same job. This is nothing against the others looking to apply for the same job, but the economy of the USA is all about competition. Some may see this as a disadvantage or advantage of our country, but the fact is that throughout one's career, competition will always be a part of the hiring process.
The second key to this first job is the experience with dealing with management to better one's position in a company. There is a tricky game of when to offer suggestions in a positive way, or when hold off on obnoxious criticism to avoid the pink slip. The first job is a great experience to learn how to contribute to the company is a manner appropriate to the position one holds. Working with other employees is also a great skill learned in the first job. One will likely be working with people both younger and older, and it is key to treat each employee with an equal level of respect regardless of where they came from or what they make. Expecting respect in return is just as instrumental as giving it out. An employee who can advocate for themselves is also one who advocates for the success of the company. While the first adult job hopefully is not the last, it is one of the most important for confidence later on.
