Chapter 1: High school
Many people find their first girlfriend in high school. Some even meet their future wife there. And Peter was no exception: this is where he meets Liz Allan, the most popular girl at Midtown High… and Betty Brant, who becomes his first actual girlfriend (when I first found out about this, I couldn't believe it).
Yeah, I know it's weird for a high schooler to be dating a tabloid secretary, but in her defense, Betty is around Peter's age, even if she works at the Daily Bugle (the reasons why she starts working at that age are explored a bit deeper in Untold Tales of Spider-Man).
Of course, the relationship with Betty couldn't last forever. It turns out that Betty's brother, Bennett—a lawyer—is unknowingly working for Doctor Octopus (who needs no introduction) through some shady connections. This leads to a battle on a ship, where Spider-Man gets involved and complicates things even further. Betty is right there on the ship when one of the thugs opens fire wildly and kills Bennett. To make matters worse, it's not long before Peter loses his powers due to a common cold and gets defeated by Doctor Octopus, who naturally reveals his secret identity right in front of Betty and J. Jonah Jameson. Even so, nobody actually believes a kid could be Spider-Man…
With her brother dead and having realized that Peter isn't the quiet, safe guy she hoped for, the two of them drift further and further apart…
And all of this because of a bite from a radioactive spider. But what would have happened if Uncle Ben had never died? Peter would have never learned the lesson of responsibility and would have probably exploited his powers to get quick fame and money. I would even dare to say that instead of being Marvel's greatest superhero, he could have been a Fantastic Four villain.
And speaking of the Fantastic Four, Peter actually tries to apply for a job with them as Spider-Man at first, but it falls through because they can't afford to pay him. That leads him to work as a freelancer for a newspaper, under the grumpiest boss alive: J. Jonah Jameson.
I think it's time to skip ahead three years after Peter gets bitten by the spider. In fact, let's jump straight to graduation day…