Happy of life

This week, Susan picked up a cheap bag at the mall. It’s got one of those cheery slogans to make you feel good about things. See how you feel about it: 

Best wish for you? Doesn’t that instantly fill you with joy, happiness, and a desire to go on to the end of the road, singing at full voice, bursting with… anger at the stupid sod who let this go?  (“Hey, I want to send you something good, but I’m a mean, grumpy bastard so you can only have one good wish instead of multiple good wishes.”)

If that weren’t bad enough, take a look at the strapline underneath that garbage:

Thow to worry, happy of life? What the hell does that mean? If I knew what a thow was, maybe I would worry. And Happy of Life? $%#@*!

I am struggling to guess what Thow to worry, happy of life started off as. What should it be? Your suggestions are welcome.