Tutoring systems provide students with various types of on-demand and context-sensitive hints. Students are required to consciously adapt their help-seeking behavior, proactively seek help in some situations, and solve problems independently without supports in other situations. We define the latter behavior as stoic behavior in hint seeking. In this paper, we propose the "Stoic Behavior Hypothesis," which posits that withholding hints achieves large learning outcomes. We consider this hypothesis from four perspectives: assistance dilemma, cognitive disuse atrophy, cognitive load theory, and goal achievement theory. In the latter part, we propose an experimental environment for investigating the stoic behavior hypothesis. [This research was partially supported by Hayao Nakayama Foundation for Science & Technology and Culture. For the complete proceedings, see ED557181.]