An impulse is just a "want" over a shorter timescale. When someone says "I want to quite X, but can't", what they usually mean is that most of the time they wan

An impulse is just a "want" over a shorter timescale. When someone says "I want to quite X, but can't", what they usually mean is that most of the time they want to quit, but for short periods of time they want X more than they want to quit. Self-control is an important part of short-term vs long-term thinking. Perhaps a more important point is whether (during the times when you want to quit X) you change things so that the times when you want X are less frequent. If you say you want to quit X, but you choose not to do the things that make it easier for you to quit X (for example, for someone wanting to quit eating between meals, not buying and keeping snacks in their house, so that giving in to their impulses is more effort) then it's reasonable to doubt your intention to quit X. People do lie, especially about their reasons for doing things, and taking them at their word would be negligent if you're a doctor who needs the truth to do your job, or even if they're just someone you want to help.