It was a JPEG. Thanks for trying mtbdudex. Your post makes sense.
I'm taking a Photoshop course soon and plan to learn all this.
I can't say the times I've:
-left focus on manual, because I was shooting stars the night before, and next morning some kids event...

-left IS off, same reason as above
-had the ISO cranked up to 800 or 1600 for a low light shot, and forgot to turn it back to 100....
After doing that, now my routine is check all setting before leaving the home, no matter how late I am running.
Still, I got burned just 2 weeks ago for having the IS off on my 70-200 L when I was shooting some deer in low light situation, did not notice it until downloaded the shots and they were just not crisp as usual.
Have fun, and hold off on the Photoshop course (IMO), take shots in RAW (always) and use iPhoto for now. Don't get too wrapped up in all the software Post Processing side, get camera mechanics dialed in first.
Learn "exposure", and all things related to that.
My 2 years of lessons learned.