It probably means that the person he loves has left, or left him. He was sad and kept thinking about the past.
He took these lines from Nalan Rongruo's "Huanxi Sand"
Who thinks that the west wind is cold alone, the rustling yellow leaves are closed behind the sparse windows, and the setting sun is setting in front of meditating on the past.
I was awakened from sleep by the wine, and the scent of tea was gone by gambling on books. At that time, I just thought it was ordinary.
(Oh my God, I can still recite it. My memory is so strong)
Nalan Fang wrote this poem after his wife passed away. This shows that Nalan loved his wife deeply and was deeply hurt.
This friend of yours probably wrote such a series of signatures recalling the past after the person he loved passed away