No "Outdoor" Pets for Me

My mom has an indoor/outdoor cat. She is a sweet and loving little black purr machine. She spends most of her days outdoors, and the nights too, during the summer, but comes inside to sleep when it starts getting cold out.

She actually came and slept with me and my mom’s dogs one night while I was visiting this last weekend. (My mother kindly gave up her bed so that I could sleep with the doggies.)
I enjoyed the little bit of time I saw Jello. She is very friendly and loves to be petted, but it made me realize, I could NOT have an outdoor cat.
She’s not my cat, and yet, when ever I was at my mom’s, I was looking for her- was she sleeping in the yard, wandering near the garage, maybe even inside eating. I always felt better when I could see her, know where she was. But when I didn’t know where she was, it made me a little nervous. I would purposely have to make myself stop thinking about it. I honestly believe that if I were to stay at my mom’s more than a weekend, I might have a minor breakdown if I went too long without seeing the cat.
Now, Jello is a perfectly happy and healthy cat. She knows where home is, and even occasionally comes when called. And my mom admits to getting nervous when she isn’t inside by a certain time when the nights start getting cold. And if she doesn’t come, my mom goes looking for her.
She’s really not in any danger and would probably be an unhappy kitty if suddenly confined to the house.
I don’t think there’s anything wrong with indoor/outdoor cats (or even outdoor cats, as long as they have a warm and protected place to sleep). I think it fits with their nature better than it does with dogs.
But given all of that, I couldn’t do it.
We don’t have a cat because C is allergic, but we both like cats. Having a cat isn’t out of the realm of possibility. But I know now, unless I’m taking in a feral cat (ie providing it with food and a sheltered place to sleep) that wouldn’t come in the house anyway, there will be no outdoor-ness to any cat I might ever own. I’m just too much of a worrier.