Wonderful poem, especially in that you avoid overuse of cliches even though the theme might tempt you.

I'm sending a cloud to
Come and rain on you.
To wash away all the wrongs and all
The lies off you.
^^^bold opening, at once simple, intimate and challenging

*cleanse

It is the only thing on Earth
That knows you better than I do.
^^^taken with the previous stanza, this stanza strongly establishes your prior connection

It is carrying my love,
A most tremendous thing to lift.
And when it finally gets to you,
I'm asking you to forget.
^^^very naturally stated, yet packs a tremendous impact by the conflict: i.e. the weight of your love juxtaposed against the demand to forget

Forget the things you've learned
And the place where you grew up.
^^^Like a call to duty or discipleship

*commit

And I hope I won't regret it.
^^^Challenge reissued, but with the understatement that you expect the person to rise to the challenge

I'd really suggest you rework the submission into some sort of meter choice. Currently, the beats are as follow:

5, 5, 9, 4 (23)
6, 9, 7, 6 (28)
6, 6, 8, 8 (28)
7, 8, 9, 7 (31)
6, 8, 8, 7 (29)
7, 8, 7, 8 (30)

It seems to me you may have a natural 7-8 beat in there.

Perfect is all I can say, 5/5

Perfect is all I can say, 5/5