You Do Need power plug adapter while traveling from Namibia to Italy.

Here is Why You Need An Adapter

The outlet and plug type used in Italy are C, F and L and in Namibia are D and M. This is how they look like.

Namibia

In Namibia, outlets of type D and M are in use.

Type D

Type M

Italy

In Italy, outlets of type C, F and L are in use.

Type C

Type F

Type L