I don't understand what all the fuss is about.
If you are operating to the Visual Flight Rules then you don't require a clearance to enter or fly in Class E airspace.
I dont understand what is meant by "...blunder into class E without saying anything first." Was the "blunder[er]" operating in accordance with the Visual Flight Rules?
If you want to change to the Instrument Flight Rules whilst in Class E airspace then you need to obtain a clearance before you can change from VFR to IFR.
Where's the hard part?