In the movie Memento, Teddy claims to have known Lenny for over a year. But if they were supposed to be acquainted for that long, why didn't Lenny have a photo of Teddy? It seems like Lenny should have had some information about Teddy that could have helped him in his revenge quest. Can you explain why this was the case?
Teddy claims to have known Lenny for over a year, but Lenny doesn't have a photo of him because he suffers from a condition called anterograde amnesia. This condition prevents him from creating new memories after a certain event, which in Lenny's case is the night his wife was murdered.
He takes advantage of Lenny's condition by manipulating him to do his bidding. Teddy tells Lenny that he's a cop and that he's helping him find the man who killed his wife. In reality, Teddy is a corrupt former cop who is using Lenny to carry out his own agenda.
And he intentionally withholds information from Lenny and gives him false leads to keep him on the hunt, all the while profiting from Lenny's misguided attempts at revenge. Teddy is aware of Lenny's condition and uses it to his advantage to further his own interests.
IMO, the reason Lenny doesn't have a photo of Teddy or any other helpful information is due to his condition, and Teddy's manipulation and deceitful tactics only further exacerbate Lenny's struggle to find the truth.