Who were we in the past life previously?
Maybe we were already a devotee in our last life and we have come back again and so on.
On the other hand it might also have been that we were a worm and some Vaishnava spit and it landed on our head!
It could have been. And by that we attained human birth and our devotional service began.
It could also been that we were a rat in our last life and somehow or other ate some prasadam -
and that is why we still have this rat like mentality!
(Kadamba Kanana Swami, Radhadesh 2010)