How can a one-year-old baby survive the destruction of his parents’ home? Hey, a Killing Curse is one thing, but how could Harry block tons of bricks and wood crashing down on top of him? As if that weren’t enough, the kid was on the second floor of the house! It would seem that Harry’s surviving the destruction of his parents’ house is an example of the fact that wizards have some sort of built-in protection against mundane accidental injury. They simply can’t be killed as easily as Muggles. Here are a few examples from the books:
Neville’s family thought he might be a Squib. In order to test him, his great-uncle tried to surprise the little fellow by nearly killing him. He pushed him off a pier into the ocean, for example (PS7). Apparently, the magic-ness in him, if there is any, will manifest itself in a surprise of that kind. Then he got dropped from an upper story window and he bounced! This built-in protection indicated to his family that he was in fact magical. In the Muggle world, this great-uncle would be up on child endangerment charges. In the Wizarding World, there’s a celebration (PS7).
Various Quidditch players are injured in spectacular ways, including, for example, ploughing into the ground at top speed. Krum took a bowling-ball-sized iron ball to the face, and only suffered a broken nose – not, as might be expected, a concussion or a skull fracture (GF8). When Harry was similarly hit by Crabbe’s illegal Bludger in the small of the back, he was only winded (OP19). In every case, they are not permanently injured and certainly not killed.
Neville again, this time in Flying class. He fell twenty feet from a broomstick. Twenty feet. I don’t care if he’s falling onto grass, this kid should be dead or at least seriously, seriously injured All that happens is a broken wrist (PS9).
Hagrid’s reaction to hearing that the Dursleys had told Harry that his parents had been killed in a car crash was particularly telling. He considered it laughable that anyone would think that a car crash could have killed them (PS4). Obviously, although car crashes seem all too deadly to us Muggles, Hagrid found them of no concern at all. (However, this may have been due to Hagrid considering it unlikely that two wizarding folk, one of them a keen flier like James Potter, would travel by car at all, not that they were invulnerable to injury.)
Notice too that Harry, before he even knew he was a wizard, once saved himself from being pounded by Dudley and his friends by levitating to the top of the school (or was it Apparition!) (PS2). It seems that wizards have the magical equivalent of “airbags,” and when danger strikes, they instantly and without intention fire off some counter or protection spell. It is also possible that they have a sense we Muggles don’t recognize which alerts them to danger in advance. After all, Harry does seem to be able to sense people that he can’t see (Snuffles, for example, in PA3), and Winky and Crouch Jr. in the wood (GF9)). Whatever the actual mechanics of it, wizards clearly are not injured as quickly as Muggles.
Must be nice.