Investing time, money and energy into a strategy, only to have the market not respond is like taking a punch. You might not get knocked out, but the effect of multiple blows can take a toll on your confidence and enthusiasm.
Some people take time off and re-assess things when they get to a point where they feel disconnected or in despair. They’re the smart ones; plenty of others fall into the “sleepwalking” stage. They’re too spent to approach their work with creativity and enthusiasm anymore, and their output predictably suffers.