In my opinion, as all things are transitory, they can't be reliable sources of lasting satisfaction.
To find lasting and secure fullness in my opinion there are two ways:
By eliminating the craving itself (like Buddhism does) or fullfilling the crave with something more reliable, often conceptual.
For the second kind it often involves perceiving or feeling one with "God" (Which is pretty much always depicted as perfect, full, and complete) or eliminating the feeling of duality we have.
