Sometimes, just one slip-up at work, an email with a typo, or some offhand manager’s comment can ruin your entire day. Instead of crossing off tasks from your to-do list, you brood over what you did and start second-guessing your qualifications. Sounds familiar? Well, that’s what insecurity at work looks like — a nagging feeling you need to learn to shake off if you want to be happy, productive, and successful at work. READ MORE AT FREESUMES