My cats are all indoor cats, with an occasional outdoor excursion under my supervision (and wearing leashes as necessary), but one day, I went out to put some bird food in the feeders, and didn't realize that the screen door hadn't shut completely. When I turned around to go back in, there was Simon, my big black cat, coming out the door. I put him back in, looked around to check and see if there was anyone else out, then went in to watch a show and correct some homework.
Two hours later, I went to take some stuff out for the squirrels, and when I opened the front door, there were two cats sitting right in front of the door staring up at me as if to say "Where the )@!# were you!" What kind of advertures they had, I don't even want to know about (luckily, I live in a dead--end with little traffic), because I'm sure I would have worried (dangers from dogs, cars, mean people, stray cats) had I known they were out there.
When I was a kid, our cat Tiger got out of the house one day and disappeared. We searched and searched, but couldn't find him. About 2 months later (!), there was a scratching at the back door. We opened it, and in runs Tiger, making a bee-line for the basement. I don't recall him being ill or injured, just scared and happy to be home.
When I first moved into my house, 10 years ago, I had just made a previous outdoor cat (who was a stray hanging out at my old apartment) into an indoor cat. I kept her in for 3 weeks (having read stories of cats that make their way back to their old homes after a move), but one day decided that she was so street smart and not a roamer that I would let her out for an hour. She disappeared. I called, and looked, and knocked on all my neighbors' doors looking for her for about 4 days. I drove past my old neighboorhood several times, and got out a couple times calling for her. No cat. I was very worried, because it was in the mid-to-high 90's every day, and I thought she'd die of heat prostration,, or was locked in someone's garage, or had been abused by someone (black cats are often the victims of human cruelty).
Then one day, as I was driving to work, I passed the little woodsy-looking area (at that time. Since then, people have cut down a lot of the trees and made it less wild, unfortunately). I thought to myself: "that would be someplace I'd like to hang out if I were Tina". So later on that day, I walked down to the area (1/2 a block away) and called and called (I'd done it before, but I was more insistant).
Suddently, this little flash of black appears (she was a very tiny long-haired black cat, thus the name "Tina"--tiny/Tina). She was meowing at me, as if she were trying to get ME to come to her, because that woodsy area was so cool! I kept calling her while walking home, and she mirrored my progress, but staying close back near the trees, until we got to some houses, the she ran home. She never strayed after that, and in fact, never wanted to go out after that.