Some of you may think it was Janice Joplin, but Kris Kristofferson wrote those words... and I don't know if he had kids when he wrote those words (though Wikipedia's cryptic biography indicates that he did), but I would never say that those words are true.
I would give up every band practice (marching, not rock). I would ignore the memories of camp outs, and I would lose what I remember about every fraternity party I've ever been to. I would forget about the nights I spent playing pool or drinking beer with my buddies. I would let John Wayne and Clint Eastwood become names that I only know from the History Channel... all of that just to think about what my girls will be doing tomorrow.
...and tomorrow isn't important to many people. Of course, tomorrow is Friday, so that's big. But, my girls won't be Easter egg hunting, or blowing out birthday candles. They won't be dating (giving me grey hair) or crying over boys. They won't be graduating or getting married, and they won't be smiling over my grandchildren.
Tomorrow will simply be a beautiful Friday in which my girls will be laughing or playing (or throwing tantrums). They'll be asking to go to the park, or asking to ride their bicycles. They'll be coloring, or running, or jumping, or pretending to feed their imaginary puppy dogs.
What's important about tomorrow, is that it is greater than any yesterday.
When I got married, I became second on my priority list. When I had children, I moved to third and then fourth. It's an amazing feeling to be fourth on a priority list and to be happier than I've ever been when I was the most important person in my life.
So Kris, my thoughts for you and for Bobbi McGee are that you realize that yesterday has past, and today holds the excitement and anticipation of tomorrow.