I went shopping last weekend, and since my capacity for remembering things is slowly degrading (sigh) I often make a shopping list when I have to buy more than 500 items. Okay, maybe that's a bit exaggerated. I mean 50 items. Alright, alright, still exaggerated. I begin to consider a shopping list when I have more than 5 items to buy and I definitely make one if there are more than 10. So, I'm on my way with my shopping list, which -befitting my rank as a software engineer- was stored on my smart phone. Just a few years ago, this might have been considered geeky or eccentric, but nowadays smart phones are so common that it hardly catches anyone's eye. I frequently take notes on my phone, for the simple reason that I have it always with me, and it's often closer than a notepad or a diary.
So there I was in the supermarket, having to check the contents of the shopping cart against my list. No problem, of course. Take phone out pocket and switch the display on to show the main screen (2 sec). Tap on main screen to show launcher window (1 sec). Drag launcher window contents with finger to scroll to memo pad application (1 sec). Open memo pad application (1 sec). Locate shopping list on application menu and tap on it (1 sec). Mind you, that's an optimistic estimation, because something might run more sluggishly than usual. For example, the phone might have discovered a Wifi hotspot and thinks it's a great idea to tell me about it. But I don't want Wifi. Now, six seconds doesn't sound too bad, until I noticed the guy next to me. He had a shopping list, too, one written on paper. He took it out of his shirt pocket in less than a second. Swish. Just like that. Han Dynasty technology beating the smart phone.
That's when I realised, there are situations when you can't trump a paper based UI.