“The single best predictor for whether folks will succeed at work is the competence of their boss, regardless of generation,” said Melissa Nightingale, a co-founder of Raw Signal Group, a management training firm. “That boss is on the hook for their on-boarding, their feedback, their career growth and more. If the boss can’t do those things, they’re screwed.”

Still, when old bosses leave and new ones arrive, there are opportunities for rethinking. Workers who benefit from leaving the office early for school pickup can say so. Workers who want more feedback can ask for it. There’s a chance to look at the way things have always been done and ask: Why?

“A lot of experts make it sound like you’re putting people in boxes based on their birth year, but what we want people to understand is that generations are clues, not a box,” said Jason Dorsey, a workplace researcher. “Just because you’re born in a certain year doesn’t mean someone knows everything about you.”

Generations change as they grow up, too. For years, Gen X seemed defined by a vexed sense of aimlessness. As Winona Ryder’s character in “Reality Bites” puts it: “I was really going to be something by the age of 23.” The angst, for many, is fading. Cue a sense of workplace confidence; they became something.

Twilla Brooks, 48, recalled that when she was starting her career, as an assistant buyer for Robinsons-May, a former department store chain, she had to be in the office before her boss arrived and stay until her boss left. She raced through Los Angeles traffic before 8 a.m., petrified of letting her manager down, because in her words: “That was what you needed to do in order to make it.”

Last year, Ms. Brooks left an executive role at Walmart to start her own marketing company. Now, with no office, she decides where and when to work. “There’s a lot more flexibility in my schedule,” she said. “Because it’s my schedule.”