At the little New York cheese and wine bar where I once worked, many regulars were friends. Many fast became friends. They were Broadway people, restaurant people, and cheese-loving people. Sometimes working pretty much amounted to hanging out with interesting folk I genuinely liked. That makes for a pretty fun job.
It's different at my Philly restaurant. Perhaps it's because our prices are higher and we're a more serious restaurant; many of our guests are old enough to be my parents, or even my grandparents. Usually we get a younger, livelier crowd later in the night. This makes for a livelier night for me.
It's not that I have a problem with older people. If you love food and dining, you're probably a wonderful customer, no matter your age. As an only child, I always hung out with the grown-ups anyway. And I do believe attitude is more age-defining than any number. But it's definitely a different vibe, and sometimes I miss being among my generation.