Spoilers for 38 Minutes, The Eye, The Siege part 3, Trinity, Conversion, The Lost Boys, The Long Goodbye
John wished to forget so many things.
The Iratus bug attached to his neck, slowly killing him.
Killing 55 Genii with the push of a single button.
Losing Ford, seeing the face of the idealistic young Marine contorted by the Wraith enzyme.
Arcturus. Allowing Rodney to convince him to proceed after Collin's death, the look on his face after the project failed, nearly killing them both.
Transforming into an Iratus and secretly blaming Carson for the whole thing.
Trapped in his body while Thalen hunted Elizabeth.
He wished he could erase the memories of much of the past 2 years.