Your last sentence is the important one. You go backwards and learn the history. Take the time and you will be very surprised what you can learn.
With the internet these days it is easy as. Such as in 1904 did you know Man United played QPR in the Charity Shield? Or what were United known before they adopted their current name. History, it is all history which fans really should be making the effort to know. Of course this is not limited to United but for every club.
In the fever zone I have a Palace fan, Derby Country, Preston North End and Forest fan around me and listening to them and learning more and more is a lot of fun. If Hatter reads this he will be pleased to know that Stockport County played FC United the other day. Coming back to this thread, FC United, a club created by United fans. OK, it may have been in protest, but it is an important fact involving Man United.