'forget' a collection's item by key within each

I was wondering if you could remove or forget an item by key when using each() method in Laravel.

I have tried this:

$Items = Items::all();
$Items->each(function($Item, $Key){
    if($Item->removable){
        $this->forget($Key);
    }
});

And I have also tried this:

$Items = Items:all();
$Items->each(function($Item, $Key) use (&$Items){
    if($Item->removable){
        $Items->forget($Key);
    }
});

And it seems to just be removing all items instead of the ones that would have my true conditional values (in this e.g. $Item->removable).

Can anyone shine some light on this?

via Chebli Mohamed