This quote is a parody of a quote from Benjamin Franklin that says "never put off until tomorrow what you can do today."  Franklin's quote means that you should be a hard worker -- that you should do as much as you can every day.

Wallenberg's quote means the opposite.  It means that you should just relax and enjoy life.  If you can put something off until tomorrow, why not wait another day?  It is the idea that you should do only what is necessary.

Presumably, living our lives on this idea would make us more relaxed and less stressed.  It might give us more time to spend with our families.