Let us have a discussion about the Courier.

The Courier in my opinion is very weird.

He has came up to me once wearing nothing but his underwear.

He gave me a letter one time when I was at a farm.

He then started randomly working in the field for no reason.

One time a dropped the letter he gave me, then he picked it back up and told me I dropped it.

I think that this mysterious Courier might be the Great Grandfather(To the 1000th power) of the Courier in : New Vegas.