After the death of my beagle,
I swore I wasn't going to adopt another dog for the foreseeable future. We had three cats at the time, I was working two jobs and had two kids to look after and it just wasn't something I was even considering.
About a month and a half later, my husband and I went to the mall on my day off for my birthday dinner without realizing that the local humane society was having an adoption event. Saber nearly pulled his handler off his feet to get to me, drooling and acting like an overgrown puppy, and that was the end of the story. We filled out the application right there and then, and my husband went and picked him up three days later while I was at work on my actual birthday.
Beyond him, the two beagle girls and the kitten we adopted when we moved into our first house, I don't think we've ever actively sought out a pet at all. They all just kind of....happen.