Has anyone noticed a change in the way they perceive time when they stop smoking NORMAL cigarettes (or anything else)?
I have been smoking for several years and have just recently quit. To my surprise, my perception of time seem to have slowed down ( an hour seems to take longer to pass). Can anyone explain why this might be or has anyone had a similar experience?
Cigarettes speed up your metabolism.
Yeah, man, I’ve had a similar experience. Wasn’t cigarettes I was smoking, though. 
You sure you don’t mean “NORML” cigarettes? 
Maybe it’s just that you’re craving them, and on the edge of your seat, paying more attention to the world, looking for cigarettes. Like if you’re hungry, time seems to pass slower because you’re far more alert looking for something to eat (or something not to eat if one is on a diet). You said you just recently quit, so I guess you might still be having cravings, even if they’re not very big. Congratulations, anywho; stay…quitted? quot? with the ability to be rightfully perceived as being without action towards the aforementioned substance?
You’tre not alone. Many smokers who have successfully quit experience the same thing.
The smoking ‘pattern’ of behaviour was part of how you constructed your time, every day. You have deleted that behaviour, and so now you are going to be aware of the change, and one manifestation of this awareness is a feeling that each hour lasts longer.
I’m very sceptical of NLP (neuro-linguistic programming) and its teachings, but nonetheless there are some interesting ideas in NLP theory. An NLP therapist would say that a part of you (inside, below consciousness) was ‘running’ the ‘smoking pattern’ for a reason, with the intention of some secondary benefit. You may or may not be aware what this intended benefit is. It’s sometimes far from obvious, and it’s not always a benefit that you can access consciously. Unfortunately, despite this good intention, the chosen result (smoking cigarettes) is not acceptable to your conscious mind. The NLP therapist would try to help you contact this part of you, the part that is responsible for running this pattern, and thank it for its good intentions, but at the same time ask it to creatively come up with alternative choices for achieving the same goal but in a way that is acceptable to you at the conscious level. So the goal is not to attack or obliterate the smoking pattern - which your subconscious will resist - but to learn a greater repertoire of choices and options from which to choose. In this way, you don’t get a sense of ‘loss’ because you are still constructing every hour of every day, you’re just making different choices and they don’t include the ‘smoke cigarettes’ choice.
I’m mentioning this just in case you like the sound of it and want to read more, although I would repeat that I’m far from 100% convinced that NLP is anything more than the latest fad psychobabble!
Its simpler than the complex NLP answer, IME. Nicotine is a stimulant. Stimulants tend to alter perception of time, although not quite as many imagine that statement. When paying attention to the flow of time, it does not seem to be moving faster; rather, the perceived alteration of time happens when one hasn’t been paying attention to the flow of time. For example, you’d look at your watch, and go “Man, its been two hours since I last looked at my watch! It didn’t feel nearly that long!”.
Basically, what’s happening is, stimulants tend to produce focus. When you become focused on a single thing (work you’re doing, a book you’re reading, a video game, etc.), you lose track of time, because you’re not thinking about it. This is responsible for the common assertion that “time flies when you’re having fun”.