This quote is an absolute favorite of mine. Sometimes there are things that happen in our lives that we simply can't control - that is just part and parcel of life. What we can control is our reaction to things. Sometimes it is hard to control our reactions of course...we are human, and we have emotions and triggers that can be tough. But working on our reactions (or our sail adjustments, in this analogy!) can be a huge way of managing how we cope and avoiding that reliance on drugs or alcohol.
Always remember that despite what life throws at you, there are ways and means of altering your course and adjusting those sails!