After all the mistakes from last week's cold medicine fiasco, odds are your character has to apologize to someone. Apologies are tricky things that can play to your protagonist's flaws. Does your protagonist tend to over compensate? Make them give a gift (or several gifts). Is your protagonist unemotional? They can sort-of apologize, but allow the other character to rant back about their apology is not good enough. Did the protagonist reveal something to another character that makes things awkward? Then make sure that there are awkward silences and statements in your apology scene. Making a mistake can be a great way to find out more about your protagonist, but apologizing for that mistake can progress the plot significantly.
Don't just go, "Hey, I'm sorry!" Have some fun with it. Add a twist. Apologies can be fun to write!