Okay, because this is relevant to a movie that came out last Friday, stop me if you've heard this one.
A spider gets exposed to nuculear radiation, and then it bites a nerdy young man named Peter Parker. The end result is Peter gaining the proportionate strength and agility of a spider, as well as the ability to cling to walls. At first he's just planning to be a TV sensation using the alias of Spider-Man, using some homemade web-shooters as a means of convenient travel, but after his failure to stop a thief that he could have easily apprehended leads to his Uncle Ben being killed by that thief, he learns that with great power, there must also come great responsibility, and abandons being a TV sensation in favor of being a crime-fighter.
This is how the wise-cracking superhero Spider-Man was born.
Part of Spider-Man's charm is arguably the fact that he's someone most people can relate to. He's not an alien or a billionaire. He's not a god or someone from World War II who got frozen in an iceberg. He doesn't transform into a raging green monster. He's just a regular guy who happened to gain superpowers, and is trying to balance a regular life with the life of a superhero.