The reason for being baptised twice for me was because my old church (dispensational) believed infant baptism was wrong, as well as sprinkling. I was ignorant of the subject so I went with it and got re-baptised. I no longer hold this view. I believe my first baptism was valid, and rebaptism was not necessary.

2Pe 1:2 May grace and peace be multiplied to you in the knowledge of God and of Jesus our Lord.