Why does love fade?

Why does love fade? What is told or what scares is manipulation. Any honest union, including a family one, is created to solve a common task together. The basis of this task: growth, self-development, gaining strength, wisdom, overcoming obstacles. This means not stopping at what has been achieved, which allows for a result greater than acting alone. The intention to create, to strive for a greater result cannot cease to exist, it will push upwards, higher, towards a greater goal.