In today's technological world gaining knowledge is easier than it has ever been. Today on the Internet anyone can download a copy of the chess annotation of games played by chess grand masters. Sometimes these are available for free and other times there is a fee associated with gaining access to these historical chess games among the greatest chess players of all time.
Why would you want to look at a game that was played twenty years ago by two grand masters? The reason is simple, you can learn a great deal from the experts. The grand master ranking is often thought to be the highest chess rating that a person can have. If you can walk through a game and see the moves, strategies, and tactics that experts use in their game then you can dramatically improve your game. Some of these grand master games even come with a commentary about which strategies and tactics are being utilized so that you can learn what the names are of the tactics and strategies. The games that come with an available analysis are especially beneficial because someone has already spent the time and energy to go through and detail mistakes that were made by each player in the game.
Grand masters often spend years, or even decades, perfecting their chess game and have played against the greatest players in the world. By doing this they have experience and knowledge that we would not be able to gain anywhere else. So take advantage of today's technology and get those annotated games and play them through and learn from them, you will be glad that you did. You should notice your game improving as well after having analyzed a handful of games.