Older Americans outlined their biggest regrets about their careers.Getty Images; Jenny Chang-Rodriguez/BIMany older Americans regret some career choices that affected retirement plans and job prospects.Regrets include not prioritizing education, frequent job changes, and involvement in office drama.This is part of an ongoing series about older Americans' regrets.For millions of Americans, retiring at 65 is just a dream.Since September, BI has heard from older Americans about their career regrets in two surveys it conducted.Over 3,000 people between the ages of 48 and 96 completed a voluntary BI survey or emailed reporters about their life regrets.