The woman who rocks need not know you are relaxing; it all can be done from inside.

Watch and you will find your muscles strained and tense with resistance to the rocking.

Go to work practically to drop every bit of strain that you observe.

As you drop the grossest strain it will make you more sensitive to the finer strain and you can drop that--and it is even possible that you may seek the woman who rocks, in order to practice on her and get free from the habit of resisting more quickly.
This seems comical--almost ridiculous--to think of seeking an annoyance in order to get rid of it; but, after laughing at it first, look at the idea seriously, and you will see it is common sense.

When you have learned to relax to the woman who rocks you have learned to relax to other similar annoyances.