I went into the college library 3 times over university and the university library four times.
College:
Once for the introduction we all were told to do.
Once at 2am to pretend we were a ghost (we had a chain to rattle and creaked the door... and then found there was no one there except ourselves)
Once to see if a specific book was there (it wasn't)
University:
Once for the introduction
Three times after I'd finished finals when I ordered some fiction books that I'd always wanted to read from the stack and read them over three days.
But for maths you need it less than other subjects. History, for example, seemed to work in the library more often than not.
That's what I think people meant by the "type".