As a hunter, it is very meaningful for us to have a remembrance of our catch. After filling ourselves with its delicious meat, after storing all the best proteins we can get, we would want something that would remind us of our great hunting experience and of our great feat. One thing we enjoyed having after catching a deer is a nice white skull for a trophy.
Some hunters bring it to a taxidermist to have it cleaned for them while some find it more fulfilling to clean and bleach their own trophies. Some, on the other hand, just wanted to save money. Some hunters may have already mastered bleaching a deer skull but some may not.