Why castling is sometimes dangerous

I'm afraid I cannot agree with you that this game demonstrates that one should not castle. Black's problems in this game have got nothing to do with the fact that he castled. In fact, after 36. Nxb7 I think I prefer black's position. Black is three pawns up and has the threat Bf5 attacking both rooks. Certainly black should not lose from this position.
What your game does demonstrate very effectively, however, is why it is important to look out for back-row mates!! Black simply needs to play g6 at some point to avoid this catastrophe.
Proves nothing but blck played carelessly.
While there are those uncommon times where castling isn't necessary, the key to using that very important move is timing...

As has been pointed out several times, the outcome of this game had little to do with castling. Black had an easily won game and blundered it away. Moral of the story? Blitz chess isn't pretty.

That's why I say that sometimes, castling can be a fatal mistake, as this can happen if you leave the King alone.
Sometimes it's necessary to delay castling but if you refuse to do it every single game like some players are advising you it's dangerous it's giving your opponent a big X where to hit you!
Don't dismiss castling or the importance of King safety the longer you delay the greater the danger
I agree with alec. Sometimes you should castle; sometimes you shouldn't. And I agree with everyone else in saying that this game is not definitive of anything. As for those of you shooting down blitz chess, I would like to say that I think blitz chess is how the game should be played. Save long, drawn out thought for theory, and then learn to use that theory in faster paced game. A player's skill is in their ability to act effectively and efficiently. I enjoy a long game now and again for the challenge and what I can learn, same as anyone, but many players I've faced who're on par with myself in a long game can't handle me in a blitz game.

There are definitley TIMES when it is a bad idea to castle on one side, or at all.
Generally, most games it IS safer to castle. I can give you examples of both.
Guys, if you disagree with the original poster, at least give a courteous explanation why, don't be condescending. That should be beneath you.

White should be irretreavably lost after 17...Qxe3. Since that happened before black's mishap, maybe it is showing danger of Not castling too :)
The thing is, pawn takes e3 was an error because it shuts down the line of attack for black on the e-file. It is usually (almost always) better to Open lines to attack than to Close them.
It is also usually better to develop fully (or within a piece of it) before intiating any attacks, unless there is an obvious material gain to be made by proceding before that. There should not be tho, unless the opp has erred significantly already.
Well, if you explain me why Im wrong I will understand, please notice that Im new to the site and doesnt have too many chess experience.
Also, what's wrong with blitz chess? Is it because the ammount of time is so small that doesn't let you think a lot? I don't really see why, so, again, if someone explains me I will be grateful.