Its unlikely that when your ex moved out he managed to take ALL of his belongings with him. Depending on individual circumstances, you’ll either be making a bonfire or putting his forgotten items to one side for him (or a mutual friend who’s been delegated the unenviable role of ‘official liaison officer‘) to collect it at a later date.
Which ever route you take, I can strongly recommend setting aside a box (or boxes) in which to put his electric toothbrush charger, odd sock, 2010 Ferrari calender and so on as and when you find them. It’s far easier to deal with his ‘leftovers’ if they’re all in one place (preferably out of sight) rather than when they’re littered about in full view. The last thing you need when you’re moving on with your new life is constant reminders of your past, especially when you’re trying to adjust from it being “our home” to “my home“.