Our cats live indoors full time because there are cars and coyotes and our cats are way too stupid to avoid these and the many other hazards outside the house. Our house is fairly small, two bedrooms and maybe 900 square feet at most. We've lived here almost two years now, and Tortie Hellion still gets lost.
It's a lot less heartbreaking when you realize that Tortie Hellion often gets lost while she is in the same room as us. She's just dumb as toast.