Issue with file size

I’m leaving my current job soon, and I’ve done some Flash work for them. So, I’m packing up all my files to leave with a coworker.

One thing that really stood out for me was one file FLA file being over 125mb. This floored me, so I went through the library looking for sounds or large images I had forgotten about. I didn’t find any, but I did discover that if I re-saved the file with a different name, the size dropped down to 1.9mb.

What’s with the DRASTIC difference?