I always had a work "smart phone" (Blackberry, Nokia Windows Phone because the company didn't support iPhones at the time). Then as soon as I retired I got an iPhone 6 (latest model in 2015). I've had it with me in my pocket of various shorts, jeans, pants, coats, etc. and could not see how anyone could live without a pocket guide to life no matter where you are.
How many square feet to an acre? Easy answer with smart phone. Nearest place for delicious fried clams, bam 1/2 dozen options with directions. Need to find stainless deck screws in Home Depot and no workers nearby, it tells you the aisle and bin location.
Funny thing was at 4 years of age mine was having problems charging as the connection didn't seem to work when I plugged it in unless I fussed with it. Sometimes at night when I placed it on my nightstand the connection would go loose and it wouldn't charge. I started shopping for new iPhones when I decided to Google the issue (yes on my SmartPhone) and found a YouTube video that solved the problem. Evidently men who use their pockets tend to then collect pocket lint in that connector. I cleaned mine out with small eyeglass screwdriver set I had and bingo it works like new. So that is the only thing to "stress" about after 4 years of pocket use in dozens of states, Mexico, Canada.