The grandfather’s injunction startled the grandson. But as the weeks pass, Scott Nicholson, handsome as a Marine officer in a recruiting poster, has gradually realized that his career will not roll out in the Greater Boston area  or anywhere in America  with the easy inevitability that his father and grandfather recall, and that Scott thought would be his lot, too, when he finished college in 2008.

“I don’t think I fully understood the severity of the situation I had graduated into,” he said, speaking in effect for an age group  the so-called millennials, 18 to 29  whose unemployment rate of nearly 14 percent approaches the levels of that group in the Great Depression. And then he veered into the optimism that, polls show, is persistently, perhaps perversely, characteristic of millennials today. “I am absolutely certain that my job hunt will eventually pay off,” he said.

For young adults, the prospects in the workplace, even for the college-educated, have rarely been so bleak. Apart from the 14 percent who are unemployed and seeking work, as Scott Nicholson is, 23 percent are not even seeking a job, according to data from the Bureau of Labor Statistics. The total, 37 percent, is the highest in more than three decades and a rate reminiscent of the 1930s.

The college-educated among these young adults are better off. But nearly 17 percent are either unemployed or not seeking work, a record level (although some are in graduate school). The unemployment rate for college-educated young adults, 5.5 percent, is nearly double what it was on the eve of the Great Recession, in 2007, and the highest level  by almost two percentage points  since the bureau started to keep records in 1994 for those with at least four years of college.

Yet surveys show that the majority of the nation’s millennials remain confident, as Scott Nicholson is, that they will have satisfactory careers. They have a lot going for them.

“They are better educated than previous generations and they were raised by baby boomers who lavished a lot of attention on their children,” said Andrew Kohut, the Pew Research Center’s director. That helps to explain their persistent optimism, even as they struggle to succeed.

So far, Scott Nicholson is a stranger to the triumphal stories that his father and grandfather tell of their working lives. They said it was connections more than perseverance that got them started  the father in 1976 when a friend who had just opened a factory hired him, and the grandfather in 1946 through an Army buddy whose father-in-law owned a brokerage firm in nearby Worcester and needed another stock broker.