The Brief: AMA means "ask me anything."

DEEP DIVE
The acronym originates from Reddit, where users can host AMA’s and respond to other users’ questions. Celebrity- or brand-hosted AMA’s will often go viral; this practice allows them to connect with fans more personally yet on a public platform.
Twitter users have also taken to hosting these tell-alls, though in a more tongue-in-cheek way. A user will tweet about an interesting experience or a controversial opinion and conclude with “AMA.” This invites other users to respond with questions, though the use of the phrase here is often more comedic than functional.
Been up since 1am with a sick cat, seeing everything in triplicate, not sure of my own name anymore #AMA
— Mark_Neitzel🤘 (@Mark_Neitzel23) February 19, 2019
My school just did the morning announcements at almost 1 PM ama
— Bizz (@BizzDK) February 20, 2019
I’ve missed my last five meals. #ama
— Pending Validation (@mattdarby) February 20, 2019