You can tell everything you need to know about a person, solely based on their love for dogs.
Loving a dog means being thoughtful. Being a fur parent takes a great deal of work. It is an honor, and a responsibility. It requires food on a semi-regular schedule, many walks, visits to the vet, and infinite amounts of fur on all your clothes. Loving a dog means enduring all of these things, and enjoying it.
Loving a dog means being patient. Dogs do not immediately understand why pooping in the house is wrong. Dogs do not understand why they cannot eat those shoes, and do not really care if they were your favorite pair. Dogs do not understand why they cannot eat people food, and will do everything within their power to make sure that they get that people food, dammit. Loving a dog means teaching them to understand these things, despite the language barrier, without negativity or fear.
Loving a dog means being joyful. You get the privilege of hearing all their funny noises, and seeing all their weird faces. You are a part of the blissful ecstasy that dogs experience literally constantly. Every time they do something ridiculous that makes you think 'this dog really does belong to me', you get to share in that happiness. Furthermore, you get to share that happiness with everyone around you by constantly posting photos of aforementioned dog on Facebook, or sharing them with your friends at every given opportunity, even when they insist that you do not.
Loving a dog means being passionate. When you love your dog, there is nothing more painful than seeing other dogs suffer. Working hard to put an end to every human-made struggle that dogs go through is one of your main priorities. Putting work in -from volunteering at shelters, adopting and fostering dogs, to just giving your dog extra snuggles before bed at night- is a major, unavoidable aspect of dog loving. You just love too hard to ever stop. It's a sickness, but look at that little face.
Loving a dog means being grateful, and strong. You are grateful for every second you get to spend with your dog, because their time here is just entirely too short. From the time you get them, to the time they get grey around the muzzle and beyond they are, and will always be, your baby. Some people get annoyed when you call dogs your children, but you ignore them, as well you should, because they just don't understand. There is an eternal bond between dogs and their owners, that only dog lovers can ever truly understand.
Loving a dog means being lucky, because to love a dog is to receive infinite and unconditional love in return. Also, the best and slobberiest kisses you could ever hope for.