"Carrying a good thing too far" is a phrase that refers to the tendency to go overboard with a positive action or behavior, leading to negative consequences. Synonyms for this phrase include taking it too far, pushing the envelope, going too far, overdoing it, and exceeding the limit. Other phrases that convey similar meanings include "going overboard," "pushing the boundaries," "taking a good thing to an extreme," and "overextending oneself." It's important to know when to stop and find a balance in our actions and behaviors, to avoid the negative consequences associated with carrying a good thing too far.