Confusion about location of + and - ?

[Brett Hoerner]

Can anyone explain the difference between these two queries?

  text:(+"happy") AND -user:("123456789") = numFound 2912224

But

  text:(+"happy") AND user:(-"123456789") = numFound 0

Now, you may just say "then just put - infront of your field, duh!" Well,

  text:(+"happy") = numFound 2912224
  user:(-"123456789") = numFound 465998192

(FWIW there is no user named 123456789 in my index)

As you can see, the queries work alone, but when combined with an AND I
always get 0 results. If I move the - before the field in my query, it
works. What am I missing here?

Thanks.