Criminally bad writing (spoilers)
The actors were good, the action was good and the plot premise was interesting. But the plot itself was terrible and so were most of the characters.
Gary Oldman's character (Wells) is both mean and dumb: he yells at the guy who just got brain surgery, denies him medication and then basically kicks him out after 5 minutes of interrogation. He could've kept him around for another couple of days just in case he remembered something, but then we wouldn't have had the same storyline...
Jerico escapes, then gets caught again. The secret agents beat him up, hit him over the head (the guy who just had brain surgery), even though he was clearly valuable at this point. Not to mention they were doing this in London, in public, which could have gotten some unwanted media attention. Good secret agents would at least get the guy in a cell before beating him up!
After Wells he gets the info about the Dutchman being caught on camera at the airport, he decides, again, to get rid of Jerico (by killing him), even though the Dutchman still hadn't been caught. He could've kept Jerico alive as backup for 2 more days, but again, this dumb mistake was needed for the plot.
After the lady and the girl get kidnapped, Wells tried to talk Jerico out of saving them, by trying to convince him their lives aren't really that important... which of course, doesn't work. He could've told Jerico the secret agents will save them, that they have a plan etc, maybe even actually attempt rescuing them, but the plot demanded Jerico himself saves the damsel in distress.
Finally. when the evil terrorist escapes with a small plane, Wells just yells and hits Jerico. He doesn't even attempt to follow his plane, to destroy it, to keep an eye out for missile launches or to do anything useful at all. I'd be surprised if Jerico would actually want to work for this guy.
Heimdahl, the evil terrorist, is one of the most generic villains ever: an anarchist who wants to destroy all world governments for no reason other than anarchy. He's arrogant, pretentious, annoying, he even treats his girlfriend badly, just to make sure nobody actually roots for him (with the "good guys" being an incompetent cruel secret service and a psycho, this was very tempting). The Dutchman was also more of a plot device than a character, because he changes sides depending on what is needed for the story, without any other apparent reason.
Basically, everyone in the movie, except Jerico, is a bland one-dimensional character who never gets any development: the good doctor, the incompetent government authority, the evil villain, the love interest/damsel in distress, the evil female henchman and the bad Russians.
Also, to nitpick, Jerico's neurological issues don't make any sense: he suffered damage to the frontal lobe as a child, but somehow, in the present day, his brain has no damage, just that part of it was simply unused… That's not how brains work. No part stays unused, especially the entire frontal lobe- that would make someone severally retarded, not psychopathic. Frontal lobe syndrome is a real neurological issue and the writers could've googled it before using it as a plot device.
Plus so many cliches: memories with the family at the beach, memories coming back in no apparent order except for what the plots demands, child being friendly to creepy stranger just so she can melt his heart, "try to remember", "I need a couple of years to make this work- You only have 48 hours!".
With such a cast, I expected a better story.