I've wondered though how this would be the case as seen it said around and couldn't work it out.
Say I've had coronavirus and know I can't get it, surely heading out and about will still spread it around if I open the door to the local off licence which had it on, and then pick up some pringles but decide I don't want them so put them back.
Alternatively I head in to the office with all of the other people who are cleared, but then I get the tube back with the NHS staff who might not have had it and touch my hand on the pole, and it still spreads.
If the rest of my house hasn't had it I'd need to stay in too right, or risk bringing it back in on clothes?
Surely people will need to remain indoors anyways otherwise loads of people will just go out and say they've tested as having had it? Or the people who haven't had it will start to resent those outside, rush out to try and get it and then the flattened curve shoots up again?