What does March comes in like a lion and leaves like a lamb mean?

I'm guessing it means it comes in fast and strong then it leaves gentler then it came in.

Explanation:

1.   in sonnet 18, the speaker wants to describe the beauty of his love, but can’t find the words to do so. the speaker says “then in mid-utterance the lay was lost” when he tries to think of the words to describe his love’s beauty.   through his defeat of finding words to describe his love, he shows his love for her.

2.   instead of describing how perfect his love is or comparing her to other beautiful things, he says she is average and there is nothing special about her.   at the last 2 lines of the poem, the volta changes the poem by saying that even though his love is average in beauty, his love for her is special and unique. so instead of praising her throughout the whole poem, he contrasts her average characteristics with his special love for her.

3.   the beloved asked the speaker to describe how he feels about her. she begins to describe what she feels but "drop the torch" and says that she can't do it because the words "hid in me out of reach." the the speaker says "nay, let the silence of my womanhood command my woman-love to thy belief" and that her silence will have to be the answer to his question.