Why a partner who supports you in crisis may clash with you in success

The speaker describes a relationship where his partner was extremely understanding and calming whenever he faced serious problems, including time in prison. Her presence lowered his cortisol and he felt no stress around her. But as his situation improved and he took her to different places, they argued constantly and the intimacy suffered. On a trip to Qatar, they fought badly for no apparent reason despite having money and freedom. He concluded that this particular woman was suited to difficult times but not to a comfortable, successful life, and that mismatch drove the eventual split.