why did I become the guardian of idrasil ?

this is the story of an average guy who is reincarnated into a very peaceful world with top tier talent.but not too over powered.the first volume will consist of MC childhood and his time in the academy.second volume will consist of him enlisting in the army . I can promise all my readers that it will be a light hearted story . the story will consist in depth explaination on all powers and abilities. I will try my best to write a plot hole free story. This is my first work . so please be patient with me. Sorry to all my readers o might not be able to give regular updates because of my exams I promise regular updates by 12 June 2020. It doesn't mean I won't upload will but at irregular intervals