in video editing every day is a school day! you can never learn everything due to different styles of TV and film and software becoming far more advanced... if i were to be using ananlogue system i would have no chance siplmy cos i dont know how to use it.
anyhoo....... back to the adequacy bit - as has already been said; it the same old 'how long is a piece of string?' it all depends on what you reguard as 'adiquate' - i would say, if you can sling some clips together in some kind of coherent order then your an adiquate video editor. however im sure others would disagree and say more knowlage is needed to be reguareded as adiquate.
at the end of the day you just carry on learning..... cos there is a tone of learning to do!