Here's a game. Go up to some person – a family member, a friend, some random person in the cafeteria. Now say, "Hercules!" After that person gets over thinking you're a lunatic, ask them what kind of an image that name brought into their mind. Chances are they imagined a big muscled dude performing some kind of incredibly strenuous task. You know, like lifting a steamroller, or maybe slaying some kind of nasty monster.
This is all to show that Heracles, himself, is actually the biggest symbol in his own story. Though we know him better these days by his Roman name, Hercules, we all know exactly what kind of guy he was supposed to be: big, strong, and courageous.
The tales of Hercules' amazing feats have become so imbedded in our culture that a person doesn't even have to know the details of the myths surrounding him to know what kind of person he was said to be. Heck, Hercules' exploits are so famous that he even gets his very own adjective: herculean. Never heard this word? Well, it means a task that requires a crazy amount of strength and power to complete. You might hear somebody say, "Through herculean effort, he lifted the weight over his head." The word can also describe something that takes a lot of effort to do. For example, somebody might say, "Through herculean effort, I finished my report on Hercules."