Why papercuts hurt so damn much

During my bimonthly rereading of Price's Psychological Mechanisms of Pain and Analgesia, I ran across this in the middle of a discussion of the relationship between tissue damage and pain intensity:

the rate of tissue damage is a direct function of protein in activation that, in turn, is a function of temperature. However, the amount of tissue damage is a function of both skin temperature and duration of stimulation. Since heat-induced pain depends only on the temperature attained by the cells of the skin and on duration of stimulation, pain intensity follows the rate of tissue damage and not its total amount. One consequence of this phenomenon is that some extensive wounds may be less painful than slight wounds. Pain from tissues that have suddenly become inflamed, such as a toothache, is an example." [Page 11; italics original]