In my early 20s I lived in Japan for a few years. Early on, before I had a phone of any type (let alone a smartphone), it was incredibly stressful – even though I had studied the language prior to arriving, it wasn't enough to handle more than the most basic situations and trying to meet and coordinate with others was a nightmare. If anything deviated from the plan, including me getting lost somewhere along the way, it all fell apart.
After having been there for a couple of months I got an iPhone 3GS and it was transformative, even though things like map apps were nowhere near as good as they are now (for example, all the location names were still in Japanese even in the English version of the app, and couldn't handle transit instructions). With it I felt much more confident in going places and doing things. Being able to text or be texted, "hey I'm going to be late" or see where I am on a map instantly such a huge thing.
This effect isn't going to be strong in one's own country of course, but it's still going to be there whenever visiting an unfamiliar area.