Kowloon celebrates its 59th birthday Thursday night. But don’t think the perpetually popular Route 1 restaurant is getting old. In fact, it’s evolved dramatically over the years.

“The secret is that we’re family-owned,” said Bob Wong, 54, the third of four generations to run the massive, 1,200-seat restaurant. “We’re not a chain. We can adapt to the market quickly. We don’t go through channels to make changes.”