Every morning when I went to feed the cat, I'd tell her to wait and she did, patiently at the top of the stairs. Three weeks in, she was growing faster than I ever thought possible. I knew the day would come when she'd follow me and I'd have to address the situation but she never did more than put her paws on the top step. Then we went to South Carolina where she went up and down a short set of steps with three other dogs. There, we stayed two nights in a hotel that had four flights of stairs outside the room and she went up and down them all (repeatedly) without ever giving it a second thought. I figured it was over then and prepared myself for her new found access to the basement at home but when we got back, it didn't happen.
Ten months old now, she still waits. Even if I leave her alone in the house, she's never ventured down there. The funny thing is, out in the world, she goes down every sort of staircase, gets on elevators, goes in and back out of Home Depot, Kinkos, the bank, you name it; she'll even ride down a slide at the park (don't ask) but the basement - still belongs to Gigi.