I'm pretty sure my name is down on many membership lists of organisations I am no longer a member of, or even interested in, or indeed, able or eleigible to attend any longer! I do not feel the need to ensure that each and every one of them specifies that I have left.
I always worry about atheists who feel the need to prove how much they disbelieve. Like love and hate, this is just two sides of the same coin. It takes a lot of time, effort & emotion to disbelieve in such a strident way - time effort and emotion that we do not put into our disbelief of Zeus or the sock monster or American redneck obsessed aliens. Personally, I think about my childhood religious education pretty much as often as I think about the "gang" I was in when I was in primary school - which is to say never unloess someone brings it up in conversaation.