Reminder: Garfield is a house cat who hates Mondays.
He doesn't need to get up to leave the house for a job.
Jon does.
The obvious conclusion is that Garfield hates Mondays because they mean his human is gone for large parts of the day, unlike on the weekend.
There is literature that cat's purr has some beneficial effects we're not exactly sure of. It definitely looks blood pressure. We think it might help mend bones faster.
Yeah, they think it's the frequency.
Honestly, I think it's something else entirely. The placebo effect coupled with improvement to our mood that we get when we have a cat purring.
Mood and lower stress does do a lot, after all.