When Neo was alive, we had two other cats. His older sister Nala who we had to put to sleep in 2017 due to her quite literally falling apart. She was 17 too. The other cat we had was a remnant of what we called Kittenpocalypse in 2014. We had been feeding a stray momma for a couple years and then the perfect storm hit. 4 pregnant mommas that all popped within a week of each other. We had 15 newborn - feral - kittens in the span of a week. We lost one because his mom (only child) abandoned him and he died before we got to him. But we rehomed all of the others except for one - Randy Butternubs.
So it was just Neo and Randy back in 2020. Randy WORSHIPPED Neo. Absolutely loved him. Neo... tolerated Randy. When we lost Neo we decided not to get another cat. We could tell Randy missed the company and got REAL snuggly afterward. Hes always been sweet, but not a snuggler until we lost Neo.
So, we decided to get another kitten, and ended up finding a bonded pair, a gray tabby and an orange psychotic kitten. The tabby (Ahsoka) LIED to us. She ended up growing orange fur and became a Torbie. Worst cat we've ever had, and I absolutely love her, shes great. Such a troublemaker and I wouldnt change a thing. Shes perfect. The orange boy (Dewford) is.. simply put, my new Neo. He didnt replace Neo, no one could. But this little guy (they are both gonna be 4 this december) has wormed his way into the same ventricle as Neo.
And Dewford WORSHIPS Randy even more than Randy did Neo lol.
Randy... tolerates him.
Apologies - The point of this tl;dr is - Don't beat yourselves up if you miss having a furbuddy around, and want to get another cat/kitten. You can't replace Garth and you wouldn't be. You wouldn't tarnish the memories and love you have with/from him. But the other kitten(s) will help you heal. I do wish I still had my Neo, (wasnt named after the console, he was named after the matrix character - his neural kinetics were WAY above normal). But Ahsoka and Dewey have definitely helped alleviate that pain.