For the last seven years, comic book writer Gerry Duggan has been writing Deadpool stories for Marvel, allowing the Merc with a Mouth to do everything from get married to murder Phil Coulson, the latter occuring on Hydra Cap's orders. Duggan's run comes to an end today with the release of Despicable Deadpool #300, where Wade takes a bunch of drugs in an effort to wipe out some of his most painful memories.
By the time Captain America and S.H.I.E.L.D. agent Emily Preston arrive at the lab where Deadpool is overdosing, the antihero is already in a comatose state, unconsciously in a hall of his own recollections, which he begins to destroy one-by-one, revisting some of the highlights of the last seven years. If that wasn't enough for you, he then wakes up and goes to stand trial in both Heaven and Hell, but due to the effect of the drugs, he is ruled unfit and ultimately sent to a mental institution.
At the end, Deadpool finally comes to his senses, but can't remember anything, except the fact that he enjoys Mexican food (see: chimichanga). He puts on his red suit, runs out of the building as the words "Another Beginning" closes out the issue, which serves as a soft reboot of the character for Skottie Young and Nic Klein, who kick off their own Deadpool series June 6. By doing away with (aka retconning) the events of the last seven years, Duggan has left a blank slate for those that follow in his footsteps.