Tara Goodfellow shudders when she remembers how she acted at her first job out of college. She once chased a 50-year-old colleague up the stairs to get to their boss first to explain her side of a story. She impulsively quit her job over the phone.

Now 38 and a career coach in Charlotte, N.C., here’s what she wishes her 21-year-old self had known: “How to manage my expectations, learn about office politics and realize that perhaps I didn’t know it all at 21.”

Ah, yes — our first jobs. Or two or three. Few people can look back at them without cringing — or at least smiling wryly — at the many missteps.

Nowadays, with the raging debate between employers and colleges over graduates’ lack of preparation for the workforce, it’s easy to forget that since the first caveman taught his son to hunt, every generation has no doubt complained about the next generation’s work ethic.

Nonetheless, some things are different now. Most companies operate with fewer employees and tighter budgets than ever before, so there’s not as much willingness — or time — to let novices come up to speed gradually. Rapid technological changes mean that some employees are much more computer-savvy but also that ideas of etiquette — what’s the problem with engaging in a conversation and rapidly texting at the same time? — may differ widely.

“There’s a paradigm shift and friction in the workplace, with three different generations interacting,” Goodfellow said.

One of the big problems for new employees is that they don’t know what they don’t know, especially when it comes to soft skills — like working with people and being self-motivated — as opposed to hard skills, like knowing how to code.

An online study, the Student Skill Index, of about 2,000 college students from 18 to 24 years old and 1,000 hiring managers found large gaps between students’ perception of their level of preparation and employers’ perception.

For example, a far greater number of students saw themselves as very capable in the areas of prioritizing work, organizational skills and leading a group than did hiring managers.

Chegg, which started as a textbook rental company and now offers academic services like helping students find colleges, scholarships and internships, commissioned the study, which was released last year.

In the past, those fresh out of college may have had similar challenges adjusting to the workplace, said Oliver Raskin, a spokesman for Chegg.

But “what we’re seeing is an exaggeration of this,” he said. Automation of many departments means jobs that once were the bottom rung now just don’t exist “and there’s a higher bar for new hires to demonstrate their value. Now when you show up, you’re expected to hit the ground running.”

But experts say they believe newbies need to think in terms even more basic than soft or hard skills, such as old-fashioned manners, grooming and communication.

Vicky Oliver, a job interview consultant and author of numerous career development books, agreed that dress codes were “hugely important. They’re a sign of respect for the place. If you’re violating them, you’re saying, ‘I don’t respect the culture.’”

Sometimes bosses will be upfront: “I wore a skort to work and my boss asked, ‘Where is the other half of your pants?’” Oliver said.

Others are less straightforward. “My boss hinted around as my tenure wore on, and I finally broke out the iron,” Polmateer said.

One of the most common mistakes workers make at their first job, Oliver said, is to appear entitled, especially if they think they’re overqualified for the position.

New recruits shouldn’t act like “this isn’t what I signed up for,” Oliver said. “If you have a chip on your shoulder, you’ll make the job worse and leave with a bad recommendation.”