I spent 37 years largely without A/C, northern climate usually being below preferred room temperature. Heating, however, was essential. Moving south, both are surprisingly necessary as the area, while quite temperate on average, has annual temperature swings from about 25°F to 105°F - requiring HVAC.

Unless you're in an unusual situation, like high desert in a remarkably well-insulated home, I suspect HVAC is so prevalent in your life you've completely forgotten it's there out of familiarity. Mad King Ludwig of Neuchwuanstein Castle, however, would find much of the year uncomfortably cold - except that he'd completely forgotten it's there out of familiarity.