A quote attributed to Sigmund Freud. It means that sometimes you don't have to look deeply for answers or meanings, and you should just take things at face value.

For those of you unfamiliar with Freud's work, he talked a lot about the subconscious, and how it sends messages to consciousness. (I'm oversimplifying things, naturally, as it would be impossible (or at any rate I'm not going to attempt) to explain Freud's theories in depth here). For example, as many parts of sexuality are repressed, they stay out of consciousness. But still they come up on various forms, most notably in dreams. Even then, a penis, for example is a strong image, so the subconscious, in order to protect the fragile consciousness, hides the penis in the shape of something else. For example a cigar. In fact, one of Freud's best known examples is that a cigar actually represents (or signifies) a penis. (So next time you have a dream in which you are fucked up the ass by a man with a big cigar - don't dismiss it - it might be sexual).

Well, as everyone knows, Freud smoked cigars. One day, allegedly, a student asked him about what this signifies. And Freud replied "Sometimes a cigar is just a cigar". (I have also heard that it was in a meeting of psychiatrists - there are different versions).

Regardless, this sentence means that sometimes, when you're looking really deeply for a meaning for something, it might just be what is really obvious.

For example, if you just got a shipment of cigars, and are really excited to smoke one, and you have a dream about smoking a cigar, it does not (necessarily) mean that you are a repressed homosexual who just want to, well, you know.

Also, if you got a birthday card with a Tweety Bird on it from your ex, and you remembered that one day you told him how much you like Tweety, you can start delving into why he got you the card - does he want to get back together? Is he trying to break your heart? Maybe it was just a nice card? Sometimes a Tweety Bird is just a Tweety Bird.