If the peaks of dopamine are very high the lows are very low and eventually the general dopamine baseline will decrease. Moreover, dopamine is the chemical of craving, of the desire to have more. After every release of dopamine we feel pleasure followed by the pain of craving for more. So, the first time you try a Lindt chocolate it melts in your mouth and pleasure spreads through your body, but the second time it is not so great and the next time even less. You need more and more chocolate to feel the same delight as before. It is a vicious circle and leads to addiction – drug addiction, food addiction, sex addiction, gambling addiction, video games addiction, Iphone addiction, social media platforms addiction, addiction to pornography, etc. Having more decreases the pain of craving.
Another important fact is that novelty and surprise bring huge releases of dopamine.