MBA: Delete files, no change in storage amount

So I'm relatively new to Macs.

So I decided to check how much storage I have remaining on my Mac, it says 31.98 GB free. Well I've been meaning to clean up my music by deleting the songs I don't listen to on albums, and I had about 5gb of videos to move to my external harddrive I never got to. So I did all that, everything is deleted from trash.

I'm feeling good, about to see approx 40gb free, click the About this Mac, click More Info, click Storage.......

...31.98 GB free.


What is the reason for this, do I have to reboot to get it to update the number? I googled but couldnt find any info.