Not-So-Sage Sunday: Why Do We Stop?

Hello again to one and all. The first thing I want to do is apologize for the lateness of this posting; Gregg has been out all day, and came back smelling of both cats and dogs, so he's only just now available to act as my secretary. I'm going to let him say a few words himself later on, too, and I promise you that this post will be a good piece shorter than my last.
Fair warning to one and all: what follows is definitely sombre in character, so if discussion of being old and the ending of life bothers you overmuch, I apologize in advance. Next week's entry will be far less depressing, I promise!
I'm a fairly old cat...Gregg says I'm eleven, as I may or may not have said. I mostly have good days, but sometimes I'm a little slow to wake or a little hesitant to jump. It sometimes occurs to me that as days pass, I'll get slower and slower, and one day I'll just...stop. I don't quite know what to make of this, since I've never actually been present when something else stops that way...but it's a little unsettling. I've heard of other animals who have stopped for one reason or other, and get the idea that you don't have to slow down until you simply run dry...you can sometimes stop outright, and that's a little more scary. I hope I don't do that anytime soon.
I post today, and on this subject, because I want to understand a little more of what it's all about. Why does it happen? Why can't people and cats and dogs and birds just keep going? Why do we have to even get old? I would've loved to stay a kitten forever, even if getting older means I know things I didn't back then. Better still, if there is no answer to these questions, why does it make us so upset? Why aren't we able to just be happy with what we have and live as long as we can before stopping? I've seen many humans, Gregg among them, who have gotten extremely upset because a person or animal they knew stopped this way. I guess it means that they don't have their friend or mate or companion around anymore, which is sad, but sometimes that sadness confuses me, and it makes me sad too. It's just not something I can fully wrap my head around, and if anyone else has any more information, I'd be glad to hear it.
I said that I never actually saw anyone or anything stop, but that's not quite true. I was in a house where a human stopped, even though I think I was probably asleep at the time. I only found out afterword, and this brings me to Gregg's contribution.
The reason I was out today is that it was my brother's 25th birthday. It was my brother to whom Kara makes reference, an incident that occurred in 2005 when Gary was only nineteen. Our family tries to make a point of getting together and having a little fun on Gary's birthday, even if it only means going to one another's house for a little while or having dinner at a restaurant someplace. It's simple, it's unassuming, it's informal and it's usually full of laughs. Today was spent at my aunt's house, where I ate a lot of food, watched a few movies and mostly just spent the day in my family's assorted company. Not many were there, but I was glad of those who were. That's why I didn't post this morning...I was awakened and told to be ready to be picked up in twenty minutes, which left me precious little time to post on the blog. Today is both a happy and a contemplatively sad day for me, and Kara's musings and questions probably reflect it quite clearly. I'll turn it over to kara to finish.
Gregg may have had fun, but he still came back smelling of other cats that weren't me. Was he petting them and not me? Why didn't he take me with him? Why did he leave me alone? It can make a lady a little jealous, I tell ya. That's all right...he'll probably love the present I left on his kitchen floor. And whether he loves it or not, I'll definitely make myself more than just available for copious quantities of cuddles tonight.