For instance: Morrowind and Fallout 3. In those two games you can pick up ANYTHING and stash it away. Do you like those candles? How about that plate? Need a soda? Well, pick it up! Those who've played these games (and Oblivion, although I don't have that one) will know exactly what I'm talking about.
The problem with this mentality is that in non-Adventure titles, you have a limited inventory. Whether this is dictated by stats or pure space allowable, you can't simply stuff everything you find down your pants. Some RPGs do have an unlimited inventory, but these are few and far between. The only RPG I've ever played that had an unlimited inventory was KoTOR.
So you eventually find yourself full to the brim. Most of the stuff you probably don't need -- even items like armor or weapons since you'll continually come across better and better versions.
I always found myself out of inventory space in Dragon Age. To a lesser extent, I have this same problem in Mass Effect. Yes, believe it or not, there is an inventory cap at 150 items. I even edited the INI file to grant me more space.
But you'll still hold onto them. Why? Because these items might be important! You don't know when or how, but if you sell an item or simply drop it, you make screw up your game!
You know this isn't true, but... what if!? I might need this fork I stole from a tavern way back at the beginning of the game!