Go is not easy at all, it is not java or ruby or c#, it is a simpler c++ (nasty side effects of using append on slices)

append_nasty_side_effect.go

package main

import (
	"fmt"
)

type user struct {
	likes int
}

func main() {

	users := make([]user, 3)
	shareUser := &users[1]

	doLike(shareUser)
	fmt.Printf("User: at index 1 Likes: %v\n", users[1].likes)

	users = append(users, user{})

	doLike(shareUser)
	fmt.Printf("User: at index 1 Likes: %v\n", users[1].likes) // actual 1, expected 2
}

func doLike(user *user) {
	user.likes++
}