It helps when you play through a strategy or RPG game, at the same time your friends/coworkers/schoolmates are playing. That way, you hear stories the next day about how:
* Fallout 2: Dogmeat got ripped in two by Cassidy's auto fire
* Arcanum: Playing INT=1 and talking with (another) really stupid NPC
* XCom1: Using the 'football' remote launcher forty-plus times to virtually clear a base.
With the message boards and game faq sites, you can read about these off beat things, but it just does not carry the same enthusiasm as telling/hearing stories from your buddies. Even if the game has no multiplayer or coop, getting real life friends involved adds elements to any game. With old classics like Fallout 1 & 2, most if not all the 'hidden' features and easter eggs have been described in depth in the most thorough walkthroughs. However, assuming you pay MSRP on release week for the brand spanking new games (and before patches make the game work), such detailed write-ups do not exist, yet. So with many friends reading many websites and with different playing styles and strategies, there is a better chance of hearing about the frills and giggles you might not encounter playing the games from just your favorite Rogue approach or Barbarian approach (or even just figuring out how to patch the DRM to make it run out of the box).
Also back in the day, when games like Fallout were new, there were no gamefaq web sites. Yup, back in those days, we had to walk 20 miles round trip, uphill both ways, just to find these games. Opps, sorry. Nevermind.