It is a struggle many former smokers experience.
Have a few drinks and, before you know it, you're puffing away again.
Now it seems ex-Prime Minister David Cameron - who has previously spoken of his battle to give up nicotine - is also no stranger to this predicament.
In a snap from the weekend's Wilderness Festival in Oxfordshire, Mr Cameron was photographed by art consultant Lucy Edwards holding a drink and a cigarette.
Back in 2011, Mr Cameron described himself as a "former smoker" at Prime Minister's Questions when responding to a question about a ban in cars when children were present.
Four years later, he spoke in the Commons about his "relatively successful" battle to give up smoking.
He was responding to a question about e-cigarettes and whether he could highlight the role they play in helping people give up smoking.
Mr Cameron said: "Certainly as somebody who has been through this battle a number of times, eventually relatively successfully, lots of people find different ways of doing it and certainly for some people e-cigarettes are successful."
Two years on and now out of the public eye, it seems Mr Cameron has turned to tobacco once again.
Deborah Arnott, chief executive of charity ASH (action on smoking and health), said: "Quitting smoking can be difficult but getting the right support throughout the process makes quit attempts much more likely to succeed.
"It's vital that smoking cessation services are properly funded and available to all who need them, whether plumber or former prime minister."
But Mr Cameron is far from being the only politician who has talked about smoking or their struggle to give up.
In 2010, then Deputy Prime Minister Nick Clegg confessed to being a secret smoker.
On BBC Radio 4's Desert Island Discs, the Liberal Democrat leader said his luxury item, if stranded alone on an island, would be a "stash of cigarettes".
And former US President Barack Obama started smoking as a teenager but promised his wife he would give up if she would allow him to run for president.
"Look, I've said before that as a former smoker I constantly struggle with it," Mr Obama told reporters in 2009.
"Have I fallen off the wagon sometimes? Yes. Am I a daily smoker, a constant smoker? No. I don't do it in front of my kids. I don't do it in front of my family. And, you know, I would say that I am 95% cured."
Mr Obama has acknowledged using nicotine gum. And in 2013, he was quoted as saying he hadn't had a cigarette in six years.
"That's because I'm scared of my wife," he added.
Maybe he could give Mr Cameron some tips.
Stop smoking advice
- Think positive
- Get moving
- Make a list of reasons to quit
- Get some stop smoking support
NHS Choices: Tips to stop smoking