Early in his competitive tennis development before achieving international stardom, Björn Borg actually struggled significantly with his temper, occasionally clashing with youth officials and facing junior penalties for racket abuse and shouting. Recognizing that explosive anger hindered his competitive potential, he underwent a monumental psychological transformation, systematically training himself to internalize his emotions and master a completely ascetic, ice-cold exterior. This deliberate emotional discipline became his trademark "Ice Borg" persona, allowing him to suppress visible frustration during high-stakes Grand Slam finals. However, this extreme internalization of stress meant that his intense emotional pressure was bottled up internally rather than expressed outwardly, contributing to the immense psychological toll that ultimately influenced his abrupt retirement from professional tennis at a remarkably young age.