The Law of Addiction states, "Administration of a drug to an addict will cause re-establishment of chemical dependence upon the addictive substance."*
This is why we say Not One Puff Ever (NOPE). Just one will hook you right back where you left off. There's no such thing as a part-time addict. It's all or nothing, friends.
You need an anchor to stay steady in choppy waters. Mine was smell. I love gorgeous smells and I didn't want to stink anymore. Every time I had a craving I smelled something wonderful. Sometimes it was my own hair! These days it's incense or a deep breath outside.
Find your anchor. It can be anything. In 12 step programs it's a higher power. If that's good for you, go for it. If it's a human person, make it so. Find that one thing that will motivate you to keep your quit precious, No Matter What.
(*From the Why Quit website)