Your body is amazing, but it is not a perfectly predictable hydration system. Natural lubrication can shift based on stress, hormones, hydration, medications, sleep, and even how your day has gone. None of that reflects your desire or attraction. It is simply biology doing what biology does.
Lube steps in as a supportive partner, helping everything feel smoother and more comfortable. When your body does not have to fight friction, you get to relax into the moment and enjoy the experience instead of working against it.