In three experiments, we examine the role of motives underlying goal pursuit and the metacognitive strategy of mental contrasting with implementation intentions (MCII) to predict the strategic use of self-regulation responses (persistence, disengagement, and reengagement) when faced with attainable, unattainable, or multiple goals. We trained half of the participants to use MCII and treated the rest as control. Experiment 1 (N = 261) underscored the role of autonomous motivation in nurturing adaptive cognitive appraisals and coping mechanisms, which facilitated persistence and progress with a difficult but attainable goal. In contrast, controlled motives undermined striving by predicting threat appraisals and giving up coping. MCII training ameliorated the negative impact of controlled motivation on goal striving by reducing threat appraisals. In Experiment 2 (N = 391), we manipulated the task to make the initial goal unattainable. Strategic goal striving (disengagement from the unattainable goal followed by reengagement with an alternative goal) was facilitated by MCII and autonomous goal motives, and culminated in increases in positive affect. In Experiment 3 (N = 432), we extended these findings to a multiple-goal setting. The research further develops the literatures on self-regulation and self-determination, while having implications for life domains where individuals pursue multiple and/or difficult goals. "Pain is temporary. Quitting lasts forever." -Lance Armstrong 1 | INTRODUCTION In Greek mythology, Sisyphus was a king punished to roll an immense boulder up a hill, only to watch it roll back down, and to repeat this action for eternity. This story illustrates one of the most evocative images of futile goal persistence. Perseverance in the pursuit of an important goal has often been glorified in ancient and modern cultures. In contrast, giving-up is frequently taken as an indication of lack of determination, as per Lance Armstrong's quote. Variations on the old adage "never give up" are commonplace in a variety of settings such as work, education, and sports. Armstrong's dubious professional behavior suggests that perhaps he is not the best person to take advice from when it comes to goal striving. Is persistence always the preferable option? Persistence and commitment are integral aspects of goal striving (Locke & Latham, 2015), with sustained effort over time often