Firstly ,welcome to the forum moreconfusedthanever,(mcte) thats a mouthfull LOL
OK, I have a theory to answer your question : It is that for many people indoctrinated over many years /born ins included it becomes deeply ingrained in their sub-conscience
For one reason or another that they leave the religion or just stop attending meetings etc.for however how long ,
remember they have not disowned the religion they have just become inactive .
Time has passed and again for one reason or another they want to re-connect with the religion of Jehovahs witnesses.
Remember they have never disowned or bad mouthed JW`s previously they had just faded away or was DF for some reason that they believe was justified anyway.
To put it in a nutshell here is how I see it.
Jehovahs Witnesses have left the (religion/truth) however the (truth/religion ) has never left them
However I`m more inclined to believe the dog has returned to its vomit .