But what? Returning to the employer you quit from seems like a terrible idea. If it was years later, maybe you could explain it away with interview BS like "changing direction" or "finding your place."

But months later makes you not much better than the guy who shows his boss an offer from another company to negotiate a raise. It might work in the short term, but then you're branded as a flight risk. The next time they need to lay someone off (or if you slip up and they have a legitimate reason to fire you) you'd be high up on their list of disposable employees, perhaps moreso because you're more expensive than you were before.