What you can't go a day without?

[Heatman]

I'm 100% certain that I can't go a day without using my smartphone. Let's not talk about food because someone can actually fast a while day without eating or drinking water, it's possible.

What's that one thing you would find it almost impossible to go a day without doing/using?

[Shawn]

Coffee. If I don't get a cup of coffee, at least one, my day is ruined.

I can go without my phone.