Go down a rabbit hole
To enter into a situation or begin a process or journey that is particularly strange, problematic, difficult, complex, or chaotic, especially one that becomes increasingly so as it develops or unfolds.
"Owning your own business is a huge responsibility that not everyone is prepared for. Are you sure you're ready to go down the rabbit hole?"
"I've stayed away from drugs and alcohol since coming to college. I have an addictive personality, so I decided to just avoid going down that rabbit hole altogether."
"Overhauling the current tax legislation is a rabbit hole I don't think this administration should go down at this point."
It's probably a reference to Alice's Adventures In Wonderland, (often referred to as Alice In Wonderland) which starts off with the titular heroine following a strange looking rabbit down a hole, after which all sorts of strange events unfold.