I'm at the age where I pretty much know what I like to have with me in terms of every-day-carry.
I like 4"x6" sized notebooks (Rite-in-the-Rain, Moleskine and Leuchtturm1917). I have a 3"x5" Rite-in-the-Rain memo book in my left back pocket pretty much at all times. And I carry a Rite-in-the-Rain BK-16 bolt action pen and/or a Pentel GraphGear 500 (0.7) mechanical pencil. I don't waste money on other notebooks, pens or pencils. These work. I like using them. They have never failed me. I almost don't feel dressed if I don't have them with me.
I figure my short-term memory is about 3 seconds long, and getting shorter the older I get. So I write down an lot of thoughts, ideas, to-do lists, names and phone numbers, and pretty much anything else that I know I would forget if I didn't write it down. At the end of the day, I enter important stuff in my calendar, to-do list or in the Day-One Journal app on my iMac.
