I'm 34. It’s not that old. But I'm having to deal with a new feeling: mourning the lives I once lived. As you get older you start driving with road behind you as well as in front. And it becomes tempting to stare in the rear-view mirror at your past lives and forget to look at what’s in front of you. I’ve read plenty of advice about not comparing yourself to others. But nobody warned me about comparing myself to my past selves. I don't mean in a life gone wrong kind of way. My life is perfectly lovely. Yet...