You’ve basically come on here wanting people to make you feel better for smoking a pack of cigarettes (which you already know aren’t good for you) by telling you that ‘oh it’s only once a year it’s fine!’, but how can they be certain that the next cigarette isn’t the one that causes damage to your DNA thus making your cells grow and multiply out of control (giving you cancer)?
Taken from cancerhelp.org.uk:
‘Overall, of all the people diagnosed with all types of lung cancer in the UK at all stages, only about 25 out of every 100 people (25%) will live for at least 1 year after diagnosis. About 8 out of every 100 people diagnosed (8%) will live for at least 5 years after diagnosis.’ I think it’s also safe to assume that those 8% don’t have the best quality of life.
Taken from Wikipedia.org/wiki/smoking#physiology:
‘Inhaling smoke into the lungs, no matter the substance, has adverse effects on one’s health. The incomplete combustion produced by burning plant material, like tobacco or cannabis, produces carbon monoxide, which impairs the ability of blood to carry oxygen when inhaled into the lungs. There are several other toxic compounds in tobacco that constitute serious health hazards to long-term smokers from a whole range of causes; vascular abnormalities such as stenosis, lung cancer, heart attacks, strokes, impotence, low birth weight of infants born by smoking mothers. 8% of long-term smokers develop the characteristic set of facial changes known to doctors as smoker’s face.’
The reality of all of this probably doesn’t bother you that much, because you are clearly already encountering the first stages of addiction.
So, in answer to your ACTUAL question, how much is smoking going to affect your performance. Well, worst case scenario, I’d imagine that cancer would affect your performance quite considerably.
You’re on a slippery slope my friend, I just hope you can see sense before it gets worse.
If you want help with your addiction, now, or in the future (hopefully before that deadly DNA-altering cigarette) do a search for Allen Carr’s The Easy Way to Stop Smoking, which is without a doubt the best book on quitting smoking.