What does it mean that the priority stack?

Maintain a small stack of priorities and work from the top.

Example: You have been ranking your priorities. You have been asking the one-thing question. You have connected tasks to goals through priority inheritance and updated your rankings as conditions shift. And yet Monday morning still finds you hesitating. Your ranked list has fourteen items. The top three all feel urgent. You oscillate between them — starting one, hitting friction, switching to another, losing momentum, checking the list again. By noon you have partial progress on four things and completed work on none. Now imagine a different structure. You write three items on index cards and physically stack them. The top card says: 'Finish the client proposal.' The second: 'Prepare the Q2 budget review.' The third: 'Draft the hiring plan.' You work on the top card. Only the top card. When you hit a genuine block — waiting on data from finance — you set that card aside and the budget review surfaces to the top. When finance responds, the proposal card goes back on top. At the end of the day, you have shipped the proposal and made real progress on the budget. Three items. One at a time. From the top.

Try this: Build your first priority stack right now. Take your ranked list from L-0684 and select the top three to five items — no more than five. Write each one on a separate card, sticky note, or line in a dedicated document. Physically or visually stack them in rank order. The top item is the only item you are allowed to work on. Set a timer for 90 minutes and work exclusively on the top item. If you finish it, remove the card and start on the next. If you hit a genuine block — not discomfort, not boredom, a real dependency that prevents forward progress — move the blocked card behind the next unblocked card and continue. At the end of the 90 minutes, note how many items you completed versus how many you would have partially advanced by splitting your attention across the full list.