It's in your average game (I hope.) You play it to win, but sometimes it kills you. You can try once, and if you succeed, then you just continue with your game.
Castling is really opinion. Here are some master games' statistics...
(Source: 10 Most Common Chesss Mistakes... and how to fix them! Written by: GM Larry Evans)
White castles kingside: 80.2%
White castles queenside: 8.8%
White doesn't castle: 11%
Also, white castles queenside about twice as black does. Plus, castling kingside usually gives the highest percentages of drawing. All the action comes out when different sides castle (or one side simply forgets it completely.)
Another highly debated subject is whether castling is necessary with the absence of queens. This is a really position-based answer, but in my opinion castling is usually less necessary with the queens off the board.
WHO'S SIDE ARE YOU ON? COMMENT BELOW AND SHOW US WHAT YOU HAVE TO SAY!!!