When can one read the general theory of employment,interest and money? I am a first-year undergrad econ student and was interested in reading Keynes' book. in the preface, Keynes pointed out that the text deals in the abstract and is meant for his fellow economists. After reading a few chapters its become quite clear that he wasn't kidding. there so many theories and ideas that I am not familiar with and most of the ideas are criticised more than they are explained.

So my question is: what prior knowledge do I need to possess to understand the book? Any books you can recommend to acquire said Prior knowledge? 
and lastly is the book even worth reading?
I don't think you should read it at any point in your carrer, honestly. It is severily outdated, ambiguous and overall not worth the time and effort put into reading it.

Try Screpanti &amp; Zamagni's An Outline of the History of Economic Thought. Undergraduates do better when studying the works of economists who have been dead for decades as what they are, historical curiosities.  

If you are really bent on reading the General Theory and/ or pretend to research history of economic thought, then I'd say after you go through an intermediate macroeconomic theory course you're good to go.