In the USA, our driver's license served as ID, especially for underage folks trying to buy beer at the local convenience store, but was hardly ever dragged out for anything else. But here in Costa Rica one needs a passport or national ID (DIMEX) to mail a letter! To avoid wearing out my passport, I made color copies and kept those stashed in my wallet or purse. It was kind of annoying at first, but now, like you, I'm happy about it!