You frequently have packages that are named after generic nouns, like time, host, file etc. There are many contexts where this same generic name makes for the best variable name: clear, short, and easy to type:
func ReadFile(filename String) {
file := file.Open(filename)
}
In Go you have to invent a new name, so invariably you will see a lot of: theFile := file.Open(filename)
aFile := file.Open(filename)
readFile := file.Open(filename)
depending on who wrote the code.