I 18 years old, working on the construction site. My friends are all 18 years old. Why are they laughing at me? Say this industry is not good

They laugh at you because they are short-sighted. They think your work is tired and dirty, and they look down on you a little, but they are actually deceiving themselves. They can't earn that much money, which is a kind of jealousy. They have a saying in their hearts that it is sour to eat grapes. That's what they did. They don't want to do such a job, but they don't want to see you earn so much money, so they laugh at you without paying attention to them.