No reason to be embarrassed!
As you have guessed, Screenshot Captor is resistant to throwing out old screenshots. That reflects my personal bias towards holding on to things in case you might need them later (SC does have some nice features for auto-filing old screenshots into folders based on date so they will stay out of your way).
However, there are a couple of ways to do what you want. Here's one way:
- Go the File Naming tab and change the "Default New File Name" to something that doesn't include the date, like "LastScreenshot".
- Then UNCHECK the checkbox near the middle of the dialog labeled "Auto sequence new file names to avoid overwriting old files".
What that will do is always keep only the last saved file, and just keep overwriting that one file as you make new captures.
(If you ever want to save a screenshot forever just do a Save As or rename that file).
The other way you could try to do what you want is to check the "Don't Auto Save Captures" option on the Miscellaneous Tweaks tab, however that's not going to work if you subsequently try to copy the image FILE to the clipboard (vs copying the image bitmap to clipboard), as trying to copy the file to the clipboard will immediately force SC to save the file to disk.