MovieMaker somehow imported years worth of video clips and saved them all together as one huge long movie but I can't find all the original video clips?  I didn't mean for them to get pasted together.

I've looked in PhotoGallery and these clips are not there.  PhotoGallery has different clips.  So I can't figure out where all the original video clips in MovieMaker are living and how do I get to them?  Or do I have to separate each clip out of the movie?  The dates of each individual clip are not visible from the movie so will the dates be lost?

I'd like to store all my videos in one place.  Why are there some videos stored in Photogallery and others in Moviemaker and how do I keep them in one place?

Thanks very much for your help, I'm a long time Mac user and appreciate some clarity on this.