Sandcastle Days

I heard an interesting phrase the other day, "sandcastle days". The context of the phrase was that if we aren't spending time at the end of our day to reflect and create feedback for ourselves moving forward, we have little chance to reinforce what we've accomplished and learned in the day. It's like building a sandcastle and the tides of sleep and time will come and wash away those efforts towards progress. I love the imagery of it and am working to figure out, how do I capture my day's castle before it washes away?