Yes, no matter what form of waiters are, they are all youthful meals, which is determined by the nature of the service industry. Because people go to restaurants to eat, not only to eat, but also to feel the environment, atmosphere, decoration, humanities and other factors here. Generally speaking, they seek a kind of happiness. If the waiter looks very old, it will naturally affect the pleasure of the diners. Therefore, after the waiter reaches a certain age, he will not use it again. Generally limited to around 27. It depends on whether you look sunny or young. Unless you can get a big promotion (a small promotion, such as foreman, will not be used again around 27), you must change careers.