the meme "I used to be an adventurer like you, then I took an arrow in the knee."
Guard : I used to be an adventurer like you, then I met this max level l0li goblin .
Or
Guard : I took an arrow in the knee , so now I cant even stop a l0li monster from entering this castle town .
The ex-hero store owner had the right idea : maybe after he was killed countless time , he quitted being a hero and gave up ever returning to his world , then he stayed in this fantasy world , opened his own convenience store , raked in money and married a beautiful girl .
Last page : only her food and her hair got burned , why didnt her clothes got burned too ? I want to see a naked l0li goblin , lol .
About the last page , the mangaka just gave some explaination on his twitter page , I guess what he said is : because of goblins 's nature , elemental damage deals more damage to goblins than physical damage .
In Wasabi's case : all physical damages only give her 1 damage , and that fire damage gives her 10 damage per second or something . But because she is LV 99 so she has over 9000 HP , so that fire means no sh!t to her .