That's like during the flip-phone/bar-phone age, you have never really carried one so why start now? A regular watch is the equivalent of the "basic" flip-phone/bar-phone. They're only good at doing one thing, making phone calls or telling time.
I never actually wore a watch frequently before, but I wear my Apple Watch daily now. I love the Mickey face, but I mainly wear it to keep up with exercise. It keeps count of all the calories burnt when I have it on.
I never miss a text or call anymore. I always have my phone on silence mode. When I wear shorts, the phone isn't hugging my body, so I used to miss text and calls. Now I know it right away. Even if my phone is in another room, I can answer calls or reply to text on the watch.
To me, it's much more than just a watch. I use it more than my phone now. The phone acts like one of those mobile MiFi router for the watch. Anyone remember those?
Finding directions and navigation is so simple, much better than using the iPhone for navigation.
There's a lot more, but I'll let you find them. It's like the iPhone when it first came out. People were skeptical, but a lot more people will see the watch owner do things and will eventually want one.
But there are some people who don't have a "smartphone", just a basic cellphone, even in 2015. I would say it's the non-millennial people. Probably age 35+. I'm talking about the land-line/answering machine/voicemail people. Not even the digital one, but the one with those mini cassette tapes.