I had a similar experience, Golfer. It was tough moment when it finally sank in.
If I could go back, I would redo senior year of college and party like a rock star.
I'd actually care a lot less about school and just accept slightly lower grades and live it up more often. I had almost a 4.0 in college, so I think I could have made a 3.7 and gone out a lot more often...and still ended up with the same job opportunities.