Ive change the settings to include just my drive but I have photos popping of from all over the place. Some I did not even know I still had around.
My library is just one big mess of media that i do not want in there.
To me, this is one of the big benefits of MC. It helps you find everything you have, and with a bit of practice/reading/searching, you can use MC to "correct" all of this for you.
If you have images in a video folder, for example, you can use "Rename, Move & Copy..." to move them to a new/proper location. Or, you can delete stuff you didn't know you still had, and don't want anymore.
It's a bit overwhelming at first, but MC is so powerful, it can/will help you get your stuff much better organized.
As rick.ca said, you
can control what gets imported, if you just don't want to see it at all; but I prefer to import pretty much everything, then organize it in a way that is useful to me.
View Schemes are your friend!
In any view scheme, if you right-click a column header, you can add a category, and on the very left of that window, the second "dot" down is for "File path" and it will show you an "explorer" type view of your files, which allows you to easily see where the selected file(s) is(are) stored in your network. This is something I add to almost every view, because it's so helpful to me. I might have music in a "good" location and a "needs processed" location, and this column lets me easily see which files are in which location.