Don't let the ads fool you, this raunchfest earns its R rating incredibly well and still manages to sustain an oddly sweet and naive tone to it as well. Steve Carrell is the titular character who does have his reasons for still having his innocence (while owning a collection of comics and action figures might make it difficult to get laid, it isn't impossible - there are geek girls too), what makes this a scream is how his friends often seem more interested in Carrell's character getting laid, than he himself is.
Funny, funny film, well worth seeing right away before all the best gags are ruined for yoj.