The quote from Milan Kundera's "The Unbearable Lightness of Being" suggests that loves, much like empires, are constructed on certain ideas or beliefs. When those foundational ideas fade or become irrelevant, the love itself can crumble and ultimately cease to exist. This highlights the fragile nature of relationships and how dependent they are on shared understanding and values. Without these, what once seemed robust can fall apart, similar to how a once mighty empire can vanish when its core principles vanish.