Why does ts eliot think April is the cruelest month?

"April is the cruelest month, breeding
Lilacs from the dead land, mixing
Desire and memory, stirring
Dull roots with spring rain..."

~ from "The Waste Land" by T.S. Eliot

I believe that he means that April is the cruelest month because it is the beginning of hope. What has been dead (the earth in winter) is now coming back to life. Spring is a time of renewal and growth. It reminds us that we, too, have the same potential. For adults, there is also cruelty in that Spring is a reminder of youth, of past springs, of time passed. There is an inherent confrontation during Spring to be awakened, to be reborn, to begin again.