Every time I drive a significant distance I refill my car when I get home, as you never know what might happen, and I don't want to be caught out. Coming back late at night when I might have only driven an hour there is an internal dialogue of "you can do it tomorrow, just head home, don't worry about it". But we are at war, and the discipline is to always fill my car. It's not about the fuel, it's about sustaining the mindset and overcoming the internal desire to rest when the goal is not yet achieved.