I have had the calling for many years, I pretty much ignored it until the last six years, mostly cause of listening to the dogma of the Witness theology for most of my life concerning this subject.
The way that I knew Jehovah was inviting me was progressive, personally I feel it is not something you all of at once feel you have, as far as any special feeling you have, well, it is special to each elect, because we are all individuals. Why does Jehovah choose one and not another, because he does according to his good pleasure. The one claiming to be of this class progressively gives up his right to life as a human, this right has been provided for by Christ's sacrifice in our behalf. Jehovah is a god of ultimate loving kindness, by his providing this new creation is a demonstration of this.