Actually, the bigger questions is not why I now suddenly like pets. If we're being honest, I think LIKING pets is the baseline for the average human being. The bigger question is why I DIDN'T like pets as a kid. And that is for two reasons:
I was overly sensory - I didn't like the germs, slobber, hair, smell, licking, tail wags, or fur balls, etc.
There were 5 kids in my church-going family, and poor mama had very little attention for all of us, and Dad was a bit aloof. A sweetheart, but not super affectionate -- EXCEPT when it came to the dogs. Oh dear Lord! I think I was a little jealous of the critters. He spent so much time and attention on them and fussed over them in a way I wished he had over me. And he admits it was a shortcoming of his, and is making up for lost time now.
But yeah - now the hair, slobber, licking, germs, smell, mess, or maintenance don't bother me, and I find myself talking to the animals and fussing over them exactly the way my father did. BUT -- I try to fuss over the kids just the same, if not more. And we all love our little golden doodle, Pixel.