What counts in making a happy marriage is not so much how compatible you are, but how you deal with incompatibility. - Leo Tolstoy
Crucial importance of willpower/self-control/conscientiousness/grit. Mindset. Mental contrasting, implementation intentions, wooping. ‘Driving the bus’.
Note there are already a number of resources available on this website that are relevant for "Willpower & Making It Happen". Look, for example, in the "Wellbeing, time management, self-control & self-determination" section in this website's "Good knowledge" area.