Does assigning value to interface copy anything?

I've been trying to wrap my head around the concept of interfaces in Go. Reading this and this helped a lot.

The only thing that makes me uncomfortable is the syntax. Have a look at the example below:

package main

import "fmt"

type Interface interface {
    String() string
}

type Implementation int

func (v Implementation) String() string {
    return fmt.Sprintf("Hello %d", v)
}

func main() {
    var i Interface
    impl := Implementation(42)
    i = impl
    fmt.Println(i.String())
}

My issue is with i = impl. Based on the fact that an interface instance actually holds a pointer reference to the actual data, it would feel more natural for me to do i = &impl. Usually assignment of non-pointer when not using & will make a full memory copy of the data, but when assigning to interfaces this seem to side-step this and instead simply (behind the scenes) assign the pointer to the interface value. Am I right? That is, the data for the int(42) will not be copied in memory?