It’s National Siblings Day. All day, I’ve ached with missing Kate, but I have PJ and my brother, Bud, so I’m not feeling at all sibling-less–just less-siblinged, I guess. That’s all of four plus an assortment of kids, spouses, partners, etc. When we were kids, our dad left us–I actually remember that day clearly even though I was only 6 years old at the time. But I’m not going to think about him, except to say that I think it may have made us closer as kids to only have Mom. She was so busy when he first left, going to school and working full time to keep food on…