Moving is a big task, and one that you can make easier with a little preparation. But if you're in a rush and leave some things behind, you could lose your security deposit or even be charged extra rent. Many landlords don't consider you "moved out" until everything is really gone.
Image from Nicolas Huk.
A forgotten cupboard or a few items that won't fit in your truck can have a bigger financial impact than you imagine. Trulia explains how:
In some [circumstances], you're not considered "moved out" until your personal possessions have also vacated the premises, which means that your landlord might be able to charge you rent for the length of time that your stuff remains in the rental unit.
Your landlord may also have to legally evict the things you left behind. Avoid any issues by making sure you take all your stuff with you when you move (or just sell it all).