You were baptized as a baby Must you now be re baptized as a 75 year old adult?

If you believe that the baptism of infants is valid then no.

If you believe that baptism is required as a testimony of the new life a believer has started on following genuine repentance and acceptance of Christ as Saviour then you will realize that the sprinkling received as a baby was not in line with this definition.Therefore you remain unbaptized and you wouldn't be getting re- baptized.

Basically, you need to repent of your sins before they can be removed by God. Infants cannot do this so you are unbaptized if you "got wet" as an infant.
Further, the purpose of baptism is to place you in an obedient position for God to remove your sins. Remember, Peter told us we need to repent AND be baptized to remove our sins (Acts 2:38). Unfortunately few teach this today.
And now why delay? Arise, and be baptized, and wash away your sins, calling on the name of the Lord (Acts 22:16).