hat What does heroin have to do with smoking cigars? Heroin is illegal so that should be enough to tell you tcigars and heroin aren't really comparable.
I think it's completely fine to enjoy yourself once in a while as long as you stay with legal substances and enjoy them with moderation. If it becomes a daily thing or even worse, your life starts to be determined by the substance, then you have a problem. However, a cigar once in a month doesn't sound too bad. Even if it was once a week, I still wouldn't worry too much.
Besides, if you give up one bad thing, you usually end up with another. My cousin quit smoking last autumn and since that he has gaines 15kg. That's quite common for smokers and I wouldn't say it's very healthy either. There are many things that are bad for you but you still do them.
One of Finland's oldest men, Arvo Ylppö, once said that "take everything with moderation" when he was asked what is his secret of long life. I think that's pretty well said and personally, I apply that.
FYI, I don't even smoke so I'm not one of those who have been brainwashed about smoking. I may have a few ciggies when drinking but other than that, I never smoke. And I have done this for years. I'm not recommending smoking or any other bad habits for anyone but I would still say if you really enjoy smoking a cigar, then having one by time to time is reasonable.
You must be one hell of a person if you can honestly say that you never enjoy yourself. Smoking is just one way of enjoying yourself, there are many others. Some are worse than the others and smoking is probably one of the worst legal ones but I would say it still not too bad. Everything with moderation.