It is a delicate balance of adjusting the dock lines just right. Lines need to be tight enough to keep your boat from bumping into the dock, port and starboard as well as fore and aft. Lines should not be so snug that the cleats on your boat take all of the strain. Sails and wind like to play with each other. If the sail is not wrapped with 3-4 rounds of the sheets, the wind will happily unfurl your sail for you.
Many boaters only worry about their boats after a storm has passed through.
None of these pictured examples happened overnight. It is wise to visually check your boat, and your neighbor's boat each time you are at the lake. These examples are intended to enlighten and educate. No warranty expressed or implied.