20 month old won't share and extremely selfish -help

[SummerLuvin]

They're not really his toys from his house, they're his toys that he's selected form the bins in the playroom......he'll go the bins, pick a car, go across the room and place it on the couch. Then he'll return to the bins, pick another toy, walk across the room and place it on the couch, he'll continue to do this until he has about a dozen or more toys on the couch. Once he's got all the toys he wants, he'll play with them one at a time at the couch and if anyone else comes even close to the couch to play with any of his selected toys, he freaks out........there could be 10 cars on the couch, he could be playing with 2, but no one else is allowed to play with the other 8......I usually try to get his attention first (he's usually in hysterics if someone's taken his toy), and i explain: "look, there's lots of cars, you can have some, i can have some, Joey can have a few and Sally can have some, WE CAN ALL PLAY. All the toys in the playroom are to be shared with everyone. You can't play with all the cars, you must share. They are not your toys, they are my toys which I am sharing with you, so you need to share with the other kids too." he doesn't like that i distribute the toy cars among "joey" and "sally", he tries to get them back, but when i insist he shares, he usually leaves the area (not nicely or quietly) and goes to play by himself with a different toy. It hasn't sunk in yet, but I'm sure it will.......

[mom-in-alberta]

I have to say that I would probably not even let the "hoarding" begin. When he puts more cars on the couch than he can physically play with at one time, I would either be getting him to pick some out to play with or finding a way to slide the others back into the general population, LoL. Our rule is if you put it down, you are done. The toy is fair game, now! (Some exceptions, of course)
I think you are right, just keep doing what you are doing. It's a tough concept to grasp, because of the age group. But it can be done!!
One thing I wanted to ask (respectfully), is why people say that toddlers "can't" share? But that they can take turns? I don't understand. Is that not the same basic idea, but using different terminology? Either way we are teaching that you don't always get to play with everything you want to, immediately when you want. Either way, it's the same social skill and the same principle, no? I understand the differences that Reggio pointed out earlier, but doesn't it just come down to semantics?