What allows you to start anew is not waiting, but saying goodbye.
让你重新开始的是告别，而非等待。
使用what主语从句和not...but...结构，强调了主动告别（saying goodbye）对于重新开始（start anew）的决定性作用。
"Let go of the past and greet the rising sun with a renewed, tranquil spirit."
"Every moment is both an end and a new beginning."
"The Earth is round; sometimes what appears to be an end is actually a new beginning."
"Only then is there room for new things to enter our lives."
"Everything will sprout anew."