(I just realized I've gotten very lazy with title capitals)
So I made a list of thing you need to leave the house because this is basically what I bring every time I leave.

Necessary Items:
1) 2 books (believe me, if you bring only 1, you will finish it and regret it)
2) Music player! (With songs or podcasts on it of course)
3) Earbuds (duh)

Optional Items:
1) iPod or device to play on (if you have one or whatever)
2) Money (if you're going shopping)
3) Sweatshirt/Hoodie (if it's kinda cold)
4) Food (because why not bring candy?)
5) Notebook and pen/pencil (for random inspiration)

I would also recommend bringing a bag, since it's a lot of stuff lol.

Yeah that's my opinion. If you bring anything else, please comment because I'm curious.