I am an old retired Engineer - when I finished my University Degree, I called myself "an Engineer' -- I realised not much later later that I was not an Engineer at all, I was then merely qualified to become one !! - There is a BIG difference. It takes years before someone can truly call themselves "an Engineer"
I see a similar thing with C25k. Although, I didn't think so at the time I was doing it - I now realise that if we do it "properly" we really don't have to put too much effort into the daily task that it sets for us. Of course, it seems enormous then and it is very satisfying to complete the tasks and we are all proud, and rightly so, of finishing them -- but a much bigger task lies ahead for us. Now comes the time to lay down a solid foundation - to use the tools we have now been given. To some extent, I am wishing that I had not gotten so enthusiastic earlier on and signed up for a 14Klm race. My training for that is kind of interfering with a more important necessity that has to be done before I can truly call myself a "runner" And that is, as I said as a sideline in another post here, to get a lot more miles on my shoes!!