My cats from the past were street wise and outdoor smart. So that is my experience. I adopted Ebony and Sneakers who were raised indoor only. I had not had any experience with indoor cats. What I have observed is that they are really naive about the outdoors and will never be able to go out on their own. Ebony and Sneakers are only allowed to go out into the fenced and gated backyard. So far no close encounters with other creatures.
In the past I had a large cat/dog door on the backdoor so my cats and dogs came and went as they pleased. I did not have to worry and I never had a problem or a cat get killed and I had up to 8 cats over the years. All street smart.
Last week I got the opportunity to observe two indoor cats of my cousin’s. They were younger than my cats and a lot more active. He let them jump onto the counters, tables and chairs. They have areas where they can sleep like above the kitchen sink on a ledge. He opens the front door and places a chair in front of the screen door so one of the cats can sit and enjoy the outdoor smells and sun. They were both outgoing and curious and did the sniff the nose ritual with me. They let me pet them right away. My cousin would pick them up and hug them so they were more easily handled than mine.
So what have I learned? I have learned that it is possible that indoor cats can be as playful and active as outdoor. Ebony and Sneakers were obviously much more controlled by their former owners and not allowed to do much. They are doing well considering and relaxing more. Can you teach an old cat new tricks? By the way Sneakers has recovered from his cold, all is well.