my cat and my dad

My rescue cat, Romeo, was doing something today.  I don't even remember what it was--begging for food probably because he's on a diet.  But for some reason I thought about my dad and tried to remember what my dad had to say about Romeo. 
Then I realized, he never met this cat.
And that made me feel really, really sad.
I got Romeo almost 2 years ago shortly after his 9th birthday.  He had had, as well as I can tell, 5 homes in the last year (before that, 1 home).  He was afraid of everything, with severe PTSD to the point where he had to be sedated for six months or have a fear-induced heart attack.  He's got some poor litterbox habits (hence the "shaming" picture).  But now that he's figured out we are keeping him even if he has litterbox issues, he is really sweet and loving and adorable and I am totally his "person" and he follows me around and constantly rubs his head on me so the other cats know I am his. 
I think my dad would have liked him.
But realizing that, although Romeo is 11 years old and dad's been gone only 5 years, they never met, made me think of everything else my dad will never see and never know.
That made me alternately sad and angry.  I don't MISS my dad much anymore, but when I do, it always knocks me for a loop.  And I have to wonder if I'm angry because he died or if I'm angry at how he died.  Would I have felt such anger, started this blog, if my dad had cancer, or died of a heart attack (what probably would have happened without the Alzheimer's, since he had at least 1 heart attack that we know of while he had dementia.  I don't think so.