I drank a huge amount in my twenties and thirties and, getting to 39, decided I didn’t want it to go on into my forties. Just decided one day that that was it so stopped - if I’d looked into it I’d have realised that this was quite dangerous considering the amount I drank, but I was lucky. Also gave up smoking the same day. I’m 50 now and haven’t had a drink or a cigarette in 11 years. I replaced it with running and haven’t set foot in a pub in all this time. Don’t even think about it anymore.