A few months back I make serious mistake during an experiment.  Thankfully it didn't actually destroy the work.  I am still super embarrassed thinking about it.  
I was so embarrassed at work last week.  My boss keeps bringing up a mistake I made months back.
user
That happens, you have to acknowledge mistakes to learn from them.
assistant
I did though, I've apologized repeatedly.  we've discussed it multiple times.  It's hard because she brings it up in front of others. 
user
Oh well that seems improper, you should bring it up to her supervisor.
assistant
She doesn't really have one.  She's the PI and her technical supervisor won't do anything.  
user