"The 40 Year-Old Virgin" is a laugh-aloud take on how difficult the human mating ritual can be. A couple of memorably unpleasant experiences with the opposite sex causes Andy to withdraw contact from womenfolk, until his misguided but well-meaning colleagues discover his "condition." Observing how reserved Andy is with people, they enthusiastically share their individual and collective "wisdom" with him while pushing him in the path of different women, anxious to make a man out of him.
The trouble with Andy is that he's locked himself into permanent boyhood. He surrounds himself with "collectible" toys, cycles to work ("bicycles are for 6 year-olds!"), and is reluctant to take on more responsible roles in his workplace, especially if such roles entail meeting and talking to people, including eligible women.
The trouble with his friends is that while they're sexually experienced, they prioritize sex over their relationships. Hence, they themselves have difficulty holding on to their mates over the long-term, which tears them up inside.
I love the portrayal of comradeship amongst co-workers in this movie. They may initially appear intimidatingly full of male bravado and enjoy somewhat perverted activities, but below the surface they are nice guys at heart and really do look out for each other. Though their initial intention is to have a lark at Andy's expense, his colleagues prove to be a strong support group that keeps him encouraged and motivated in his quest for a mate. And it's all not just focused on Andy either; the guys also help each other out in times of personal crisis. Ya gotta' have friends amongst your colleagues. It gets sad and lonely otherwise.
Thanks to his friends, Andy, the 40 year-old man-boy learns to grow up and put away his childish things. When he does, a whole new world of adventure in adult relationships opens up for him. He may be a late bloomer, but better late than never.