Yeah, I mean the more people have seen magic, the more they know what to look for. I think the majority of people do not think that the magic we perform is actually real. There's a difference between completely fooling the crap out of people and full-on belief. You can sometimes get that real belief with either children or by performing really, really emotional, powerful magic and/or crazy, freaky **** lol.
The other side to this is that many spectators can recognize it is not real magic but still appreciate the feeling it evokes in them ( my favorite type of spectator). When I first saw magic for the first time I didn't really believe what I was seeing was real magic. Instead, I was feeling the amazement of the unknown (sounds cheesy I know lol).
Also, I think part of the family thing is that some people just get tired of it. I know exactly how that is. I think we all do. lol