not rowing with both oars

Not rowing with both oars is another way of saying that someone seems to be lacking some sort of intelligence or common sense. While it can be used for anyone who seems a little bit stupid or lacking education, it is primarily used for people who go about life with the attitude and mannerisms that they are just not all there. This may be due to lack of common sense, lack of education, or simply not having the intelligence most people have at the age they are.