Why does my mom force me to use sunscreen?

every hot day when im about to go outside my mom says you have to apply sunscreen so i run to the back door because I cant stand the way it smells and its to sticky but eventually she caches me and holds me down in her lap takes of my shirt and starts rubbing it in she puts it on my face neck which feels disgusting!! then she puts it on my legs and feet then my arms and i try to wiggle free but she has a tight grip i say ewww yuck she says hold still the she rubs it under my armpits and while she does that she starts tickling me but she says will you just hold still in a babyish-voice and its not me its the sunscreen HOW IS IT THE SUNSCREEN