You don't have to check out every attractive woman you see as if she'll be the last attractive woman you see. There are plenty of pretty people in the world (say thank you); you'll keep running into them. You being you, you'll appreciate them, and you can appreciate them, but dude, less intensely, capice?
You'll see the last attractive woman you'll ever see...eventually. In a while. In a very very great while. (Heck, she might not even be born yet. (...you dirty old man.))