The practice of "letting it be," no matter what or whom we apply it to, is really an invitation and permission slip to ourselves -- to drop into and be in this very moment, with what it actually contains, and to stop having to reject 'now' in the hopes of a different 'now.' This is the true gift of "letting it be."
Each time you hear yourself saying or thinking what "should" be happening, flip it around and ask the question, what is happening? Drop your fight with reality, your narrative about what "should" be, and you'll discover that reality, unburdened by your opposition, is a lot different than you think. The surest way to find peace is not to win the war, but to stop the fighting.