Am I addicted to smartphone?

I think my iPhone has destroyed my brain. I really do. I used to listen in meetings; now I browse the Internet. I don't text people using proper sentences anymore; I use ugly contractions such as "def" or "prob", and that's when I'm not resorting to smiley faces and winks.

I've had entire conversations in emoticons.

When did mobile devices, with all their early brain-training promise, become so dangerously addictive?