Read the dictionary properly (link). Definition 5 of a theory:
a particular conception or view of something to be done or of the method of doing it; a system of rules or principles.
That describes it perfectly so try using a dictionary yourself more often. This reminds me of the case of evolution where the scientists had to define what a theory is.
Let me explain something to you about dictionaries: Those definitions that are listed first are considered the best definition; you offer us definition #5 just barely above guess or conjecture.. I read the links I post and I understand them. I think guess describes you idea perfectly. In order for you to have a system or method, you must offer more that "I think this so it must be correct".