When humans solve problems, they can frequently rely on a multitude of cognitive mechanisms. For example, arithmetic operations can be implemented mentally, with fingers, a calculator, or with pen and paper. But how do humans decide which mechanism to use? Here, first, we will introduce well-known reasons from previous cognitive science research: most prominently, actual and believed performance of the available mechanisms. We then move on to some of our recent research targeting perseveration behavior. Why do many individuals prefer sticking with one mechanism rather than mixing several mechanisms? Multiple reasons are conceivable. First, avoiding effort might lead to switch avoidance on the one hand and avoidance of mental mechanisms on the other hand. Second, and contrarily, participants might seek mental challenges and prefer mental mechanisms. Third, bindings between similar stimuli and specific mechanisms might develop over time, which would favor repetition of a specific mechanism via retrieval of a stimulus-mechanism-binding. Fourth, participants might satisfice and stick with a good enough mechanism that allows avoiding excessive performance monitoring of the available mechanisms. In the presented research, participants engaged in an object comparison task that could be solved via one of two mechanisms: mental or manual rotation. Interestingly, and in contrast to the four reasons introduced before, perseveration was found to be mostly due to actual and somewhat due to believed performance differences between mechanisms. With few exceptions, perseveration might thus be caused by the usual suspects: actual and believed performances of available cognitive mechanisms.