Whenever someone tells me they have no time to exercise, I think of my dog Max.

For years I thought it would be nice to have a dog. I'd see people walking in Central Park with their dogs; I'd run into people on the street with their new puppies; I'd visit friends who seemed to have great relationships with their pets, and it always seemed like such a cool thing. You know, you have this dog, and it provides companionship and unconditional love, and it's a conversation starter on the street, and it looks really cool on a Christmas-card picture.

But when I started to think about the responsibilities, I'd hear my mother's voice in my head saying the things she'd always said when I was a kid and begged for a puppy: "Who's going to walk it? Who's going to take care of it? Who's going to feed it? Who's going to take it to the vet? It's cruel to have a dog in the city … " Well, you get the idea; it's not exactly a unique scenario.

I was working as a personal trainer. I was getting up about 5:30am, working back-to-back clients till about 10am, running back to my apartment to write a column, going to the gym to work out, then seeing more clients or preparing for a lecture. I was living alone; a dog seemed like a really bad choice. It just "couldn't" be fitted in to my lifestyle.

Then one day, I really wanted a dog.

I mean REALLY -- not just intellectually, not just as a concept. Maybe I was ready to take the intermediate step between solitary bachelorhood and responsible connectedness. Who knows? I just remember that something shifted from the abstract "It would be nice if … " to a definite "This is something that needs to happen."