If you find yourself coming up with great ideas at odd times, are terrible with remembering lists, or can't seem to keep track of verbal invitations, then a pocket notebook is the thing to have. A Panama Notebook like this one from Smythson are great, and perfect for those still into the art of writing down notes by hand (which tends to improve data retention). While there are alternatives like those offered by field notes, these Panama notebooks are a bit more sturdy, due to their leather covers, meaning that will not fall apart after a month of it living in your back pocket. In terms of size, it's about the size of a medium stack of 3x5 cards which isn't too cumbersome for a pocket while still being worth the price tag.
Available on smythson.com on sale for $30
Full Disclaimer: By clicking "Buy" and purchasing an item from this retailer, we here at What is A Gentleman receive a commission to help keep this site running.