If you’ve thoroughly explored Acts One and Two, you’ve no doubt noticed a veritable plague of clickable sword or spear + shield wielding corpses, scattered variably around the levels. You find them on the surface and in dungeons, near waypoints and far from escape, near dungeon entrances and off in the boondocks. They’re Dead Adventurers, and the tragedy of it is that there don’t seem to be any live versions of them.
You see lots of living NPCs in towns, and sometimes in the dungeons, but they’re all lost guards or cowardly soldiers or fearless merchants; never do you meet any aspiring adventurers like yourself. It’s as though your Nephalem ventures forth into the world once all of the brave humans have already perished, generally after collecting just a stack or two of gold and maybe a junky blue item. (No wonder they died.)
Worse yet, none of them are found in Act Three. Try as they might, none appeared able to progress past Belial (giving them something in common with most Ironborn Hardcore characters.)
There are many other fallen non-heroes; dead villagers enough to populate a town, occasional deceased “plunderers” who usually went to their deaths foolishly gripping two-handed weapons, and other miscellaneous riffraff. But the greatest sorrow must attend the fallen Adventurers, who perished chasing their dreams.