WHY DO CHARACTERS ADVENTURE?

Let me begin by saying the following is in no way a condemnation of anyone's character back story or chosen motivations for their characters. The intention here is to speak to those earliest reasons for adventure in the core of early editions and how a simple concession explains so much. 

The simplest explanation is that early edition adventurers were generally supposed to represent commoners or folks early in their professions who turned to adventure as a means to advance those careers and make their way in the world. With this in mind, the question of "why would my character go into a dangerous dungeon?" or, in other words, "What's my motivation?" becomes a simple matter of economics. 

Working any trade in the game world is not likely to earn a person more than a few gold pieces a a year, let alone the hundreds or thousands they would need to purchase proper arms and equipment for any advanced career. In old games, PCs started out with barely enough money to get them out the door and on the road and the only way they would afford the things they needed would be to delve into dungeons where ancient forgotten wealth was theirs for the finding and taking. 

Sure they could have stayed on the farm and toiled a way for some lord, or lived in the shadow of the old mage that instructed them. Soldiering is a profession but few men live long enough to make a life of it. Clerics who stayed in their cloisters, while serving their gods in the most mundane and functional ways, would never expand the reach of their gods and the power of their church. While thieves might be one of the easiest character classes to find motivation for, paladins and rangers need somethin to pit themselves against.

All of this leads to dungeons (and dragons) where a lowly adventurer can find the chance to transcend beyond a life of labor and obscurity. In this we have the most basic, yet very satisfying motivation for adventure - desire and objective. Why the character continues to adventure can build off of this or transform, based on their adventures. 

A fighter who seeks his future through adventure for mere money, may discover greater evils that call him to further action. what was just a search for gold and goods can easily change into what is, if not a higher calling, at least a slightly more elevated one. Discovering the mysteries of the world through dungeon crawling is bound to open an adventurer's eyes and either call or force them to rise to the task. 

Going forward, I hope you will perhaps consider taking a deep breath and relaxing some before you plunge into the chore of coming up with complex motivations. Let your fighter be a soldier returned from a recent war who wants for more. Allow you cleric to be a person devoted to their gods and taking up the simple charge of going out into the world and confronting the evil there and spreading the good of religion. Rangers wander and seek the evils of the world and form a outlying bulwark against the monsters of the world. Wizards need stuff and knowledge, bards need stories, and thieves need to improve their skills and steal stuff. 

It doesn't have to be epic or involved to be good.