子类继承父类后为什么不能使用父类的session？

<code><?php
namespace Home\Controller;
use Think\Controller;
class CommonController extends Controller{
   public function __initialize(){
         session('name','lili');
   }
}
?>

<?php
namespace Home\Controller;
use Think\Controller;
class UserController extends CommonController{
    public function user(){
            echo session('name');
    }
}
</code>

<code><?php
namespace Home\Controller;
use Think\Controller;
class CommonController extends Controller{
   public function __initialize(){
         session('name','lili');
   }
}
?>

<?php
namespace Home\Controller;
use Think\Controller;
class UserController extends CommonController{
    public function user(){
            echo session('name');
    }
}
</code>

<code><?php
namespace Home\Controller;
use Think\Controller;
class CommonController extends Controller{
   public function __initialize(){
         session('name','lili');
   }
}
?>

<?php
namespace Home\Controller;
use Think\Controller;
class UserController extends CommonController{
   public function __initialize(){
         parent::__initialize();
   }


    
    public function user(){
            echo session('name');
    }
}</code>