The exile in "The Wanderer" knows better than most that existence is transient, meaning that it is not permanent and passes with time. After all, once he had a home, a lord, and loved ones, but in the blink of an eye, all that disappeared. When he combines this experience of loss with his knowledge of how all men die eventually, he can't help but reflect on how not just humans, but all of creation will eventually "fail and fall." The poem expresses this awareness of transience with the image of fallen bodies in front of a wall that decays without its occupants to maintain it. It implies that one day the earth, too, will suffer the same fate. The only thing that escapes the inevitability of transience is God whose "fastness" (stability) contrasts with the fleetingness of everything else in the poem.
Although "The Wanderer" contrasts the stability of God with the transience of creation, it does not present God as a "cure" for this transience.
As it does with sadness, memory provokes the awareness of transience by forcing the speaker to relive his loss.