Does Loki work better as God of Mischief or God of Lies? Because keep in mind, as God of Lies, Loki could have the power to make someone incapable of telling lies. Which could be like the movie "Liar, Liar" or that House episode "Social Contract" where a patient's inability to stop himself from saying whatever he thinks is ruining his life.
Maybe Loki had something to do with the big Mindwipe regarding Peter Parker's identity. Almost everyone who knows *a* truth has that truth blocked from their minds.