The most common power-up in the Mario world, Super Mushrooms, like most shrooms grow.. pretty much anywhere that has good ground (they can also appear in blocks, like any other power-up can) and can either help someone recover health, or make them grow! It depends on the person, but you'll definitely be feeling stronger upon having one of these. Most bricks around the Mushroom Kingdom are fragile, and it'll usually take a Super Mushroom to crack them open!