The explanation for my error was simple:
I usually compose my emails and other documents in Word. If you are sending multiple emails during a single on-line session, the email template will retain the address(es) of the previous recipient(s) and the previous subject line. In the case of the “wallet” email, I added everyone’s address to that of the recipient of the previous email (my daughter) but neglected to delete the previous subject line and paste the new subject, even though I had copied “No Sweat” from the body of the text itself.
My excuse for this (probably) tedious explanation is to point out that not all human actions have a meaningful connection with other actions. The placement of “wallet” as the subject of the text of “No Sweat” did not have any metaphysical or deep symbolic meaning. It was purely a screw-up. In this world, coincidences can be insignificant,** correspondences can be irrelevant, and seeming causes can have no relationship to effects.
Then again, it might be “The Normalvision Code.”
****The layout of the poetry book from page to page caused the confusion.
**Freudians in the audience, please refrain from making something of the obvious (?) female sexual symbolism of "wallet."