Set person is of ''low'' too ''fucking low'' intelligence and is easily noticed by their illogical and irrational behavior which almost always ends in their public humiliation. The skills that they possess to understand their surrounding environment and the society they find themselves in are extremely poor.
A 'Vimmer' is completely oblivious to the level of his abilities and usually thinks that they are better at doing tasks then they really are. Absolutely reckless with their actions which too often lead to stupid results. People who fit into such brackets do not end up achieving anything significant in their lifespan, rather their purpose in life is to provide a bottomless pit of humor for those around him/her.
i.e. Don't be a 'vimmer'