Well water tends to be "hard" water, meaning a high amount of minerals tend to be dissolved in it- calcium, magnesium and sulphur, mostly. The sulphur is why some people who have hard water have water that smells like rotten eggs- their well or aquifer has a higher amount of sulphur than wells that don't have that smell. People who use well water tend to use water softeners and also tend to use systems that filter more from the water. However, these set ups are usually done within the house's water system, not on the well itself. As a result, tap water inside the house is usually not as bad about causing layers of calcium to form or about tearing up machines that use water, but water that comes from outlets not on the house system still has all of the dissolved minerals in it. As a result, OP had probably never seen enough calcium buildup on dishes and the like to know that they had hard water.