A thirtysomething on a flight said she's penned a "Must Do" Journal since she was a teenager. It's not a list of things to do, but rather a list of things she wants to remember she liked and/or "Must Do" when an occasion arises.
If she goes to a dinner party, wedding, baptism, conference, meeting, etc. and sees something unique that could be a "must do" in her own future, she writes it down in a "Must Do" Journal. Also includes memorable toasts, wording on invitations, notes of encouragement or other expressed/written thoughts for potential future use. Example is going to a wedding year ago where bride had baskets of different size slippers for the guests - heels and dress shoes went off and everyone could dance for hours in comfort. She's engaged and that "Must Do" will come into play.
Putting it in a specific journal (even an online one) a great idea. How many great ideas do we never use because we forget when the occasion or opportunity comes up in the future?