In my English compostion class we actually had this discussion with many popular phrases like this. Our school had people from different parts of the country and what we found out was that people in different parts of the country say things differently. It may not necessarily be that one way is right or wrong, it just doesn't seem "normal" to everyone else. An example that stuck out with me was the fact that the kids from the South (Texas, Oklahoma, Louisiana, Mississippi, etc.) tended to say "accrossed" instead of "accross." For example, "The wind blew acrossed/accross the state." Our teacher explained that it wasnt wrong to say accrossed, but it was just an evolved way of the word accross. The way things are worded over time becomes kind of like the game telephone. Another way to look at it is when European-Americans came to America through New York in the 1700's the people writing down names would sound out the name and write it how they thought it sounded. My lage name is Lage but it could have very well been Large, but the person recording the name could have forgotten the 'R' or it just got lost in translation somewhere along the lines. That is how I look at the way phrases are worded. No way is particularly right, nor wrong.