Well the core currency in GW2 is still gold, but you do collect things that are traded in for other things. I never got too deep into GW1, but my friends who've been playing that since launch say there's tons of those collectable currencies. *shrugs*
Guild Wars 2 is different in that most of the currencies are very specifically designed to either not interact with, or have extremely limited interactions with gold. In Guild Wars 1, the concept of 'bind on pickup' didn't exist, so everything could be exchanged for gold.
In Guild Wars 2, you can't directly exchange between Gold, Karma, Ascalonian Tears, Seals of Bettletun, Deadly Blooms, Manifestos of the Moletariat, Flame Legion Charr Carvings, Symbols of Koda, Knowledge Crystals, Shards of Zhaitan, Fractal Relics, Laurels, Skill Points, Guild Merits, or Badges of Honor.
And in addition to that, there's also Influence (one-way conversion from Gold of Influence possible), Gems (two-way conversion between Gold and Gems, although you lose a certain amount of 'tax' in the conversion), and Mystic Coins (two-way conversion possible).
Your friends are probably thinking of the Collector items in Guild Wars 1. And while there are a ton of those, nearly all of them are zone-specific, are common drops from the relevant enemy type, and you almost never need more than 5 of them to buy an item - and all of the relevant items you can trade them in for have equivalents that are easily available to be traded for gold.