When someone jumps the bandwagon, they are following a trend or popular opinion without much thought or consideration. There are several synonyms for this phrase, including "jump on the bandwagon," "go with the flow," "follow the crowd," or "conform to the norm." All of these phrases suggest that the individual is not making their own independent decisions, but rather taking the easy route and simply going along with the masses. Other related phrases include "sheep mentality," "mob mentality," and "herd mentality," which all describe the idea of individuals blindly following others without any critical thought or analysis. It's important to be aware of these tendencies and think critically about our own decision-making processes.