To a Younger Coworker: “Considering this is your first job, you probably wouldn’t understand.”
This statement is dangerous in that it assumes the following two things: 1) That this is your younger coworker’s first job and 2) That your coworker would thus probably not understand.
This is certainly one of the worst things you can say to a coworker because there’s no way this could be construed as a harmless comment. It’s an attack, presumptuous, and just downright rude.
Don’t assume this is your coworker’s first job just because she is young. Lots of younger nurses get valuable, hands-on experience via internships and volunteer work. And never assume of any coworker that she wouldn’t understand. It’s a surefire way to make instant enemies in the workplace.