Sometimes the foundations of openEHR can be difficult to understand especially in our "now" world.
There is a lot of specific information on openEHR on this website but without the proper context it can make the specifications seem overly complex. This isn't the reality and in fact these specifications are actually quite simple in the scope of health information. There are many textbooks and papers that can help with the study of information theory and an understanding of openEHR foundations. I believe that it may help newcomers to spend sometime taking advantage of YouTube and learning about information in general by viewing Gary Marchionini's lectures from UNC at Chapel Hill such as this one These are not healthcare specific but I believe that they can help those new to health information management and systems design understand more about why openEHR specifications are designed the way they are.
Certainly Claude Shannon is considered the father of information theory and this page is a good overview of the Shannon-Weaver model. This quote is particularly compelling: "The Shannon-Weaver Model, in common with many others separates the message from other components of the process of communication. In reality, though, you can only reasonably examine the message within the context of all the other interlinked elements." IMHO, the last sentence is the most important where it states that the context and the interlinked elements must be there to achieve communications. Note that this is speaking about the "message". However, without having the complete semantic context avaible (which is what the openEHR information model is about) then you cannot construct a complete and proper message.