Because you will love it dearly.
Because one night when you can’t sleep you’ll reach out to her for comfort but she’ll be on the other end of the bed, so you’ll roll back over lonely, and she’ll somehow know to get up, turn around and lay back down directly under your outstretched arm.
Perhaps a sea turtle, who lives near the ocean, who buries her eggs at night in the darkness, under the stars then forgets. Who sits for hours in the sun unmoving, whose hard shell makes her unfit for any form of petting, boring, who will live, we expect, longer than you, for hundreds of years.
Come to think of it you can’t have the toy at Christmas either, that will bring you joy for weeks until it wears out from use, or a best friendship, or a first love, or God forbid kids, because things like these break-up, or break down, or brake at stoplights far too slowly.
No. It will be better for you to be curmudgeonly, cynical, surrounded by the trappings of modern society which when damaged or stolen can be repurchased or upgraded nonchalantly, utilities of glass and metal replaced at the slightest hint of slowness or a newly released model.
Because love happens. Because things die. Because dear friends often move on before they grow old with you. Because you will die too. You will leave behind people who love you. Who think your passing, no matter your age or theirs, will be far too soon.
Who’s going to take care of your puppy then? Mopey, distraught, inconsolable.