While Marvel Comics houses super-intelligent heroes such as Tony Stark, Reed Richards and Hank Pym, right there alongside those names when it comes to the 'smarts' ranks, is Peter Parker.
If Peter isn't an equal to Tony, Reed and Hank, he's only a minor notch below them, with few characters in the Marvel realm being as skilled as Spider-Man when it comes to science and technology. Oh, and quipping wise. Always, always with the quipping wise.
Despite being able to turn his mind to pretty much anything, though, there have been times over his 60-year run - ol' Web-head debuting back in August 1962's Amazing Fantasy #15 - where Spidey has been left with a conundrum that even he can't find a proper answer for.
Here, it's all about spotlighting some of those major moments where Spider-Man simply couldn't find a solution to the problem that was staring him square in the face. That could be having to make major decisions, struggling to work out a viable explanation for something, or simply being tasked with a puzzle that the Wall-crawler is unable to solve.
With that in mind, then, here are eight such times when even the great Spider-Man was left stumped by a particular mystery or riddle.
8. The Truth About His 'Parents' - Lifetheft
The '90s was a slightly bonkers time for comics, with ludicrous stories, some garish characters redesigns, and a general feeling of needing to think completely outside of the box. One prime example of all of this, is 1994's Lifetheft.
Looking at ways to bring something different to the Spider-table, Marvel Comics opted to have Peter Parker's long-dead parents Richard and Mary return from the grave. Previously said to have died in a place accident years ago, the Parkers turned up at Aunt May's door in 1992.
For almost two years, Richard and Mary would connect with their son, explaining how they'd actually been kept as prisoners by Russia during the time that they were presumed dead. It took only a matter of weeks for Peter to let his ma and pa know that their boy was Spider-Man, which resulted in Richard doing his best to instil a harder, tougher edge to his son's superhero antics.
Unfortunately, Spidey was so caught up in all of this, he failed to see the truth about his 'parents'.
Once the Lifetheft arc rolled around in 1994, it was explained how the real Richard and Mary were indeed dead. Instead, these 'returned' versions of the Parkers were actually Life-Model Decoys created as part of a scheme involving the Chameleon, Vulture and the Harry Osborn iteration of the Green Goblin.