The hardest part of quitting anything is changing the behavioral habits that came with it.

For smoking, I bet you have the urge after a meal to smoke. Maybe you’re triggered when you drive long distances to “calm the nerves”. The issue is those triggers, those behaviors, need to be unlearned before you can attempt to quit. That’s why it’s easy for people who haven’t developed those behavioral habits and hard a hell for those who have. Former smoker myself so I totally get it. I can give that up, but caffeine - coffee? I’ll die with a cup on the counter half full.