Two people with insatiable appetites are never satisfied

It is narrated from Sayyiduna Anas (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "There are two greedy ones who are never filled: one greedy for knowledge who is never satisfied, and the other greedy for the world who is never satisfied."
This hadith is sahih (authentic) on the condition of the two Shaykhs (Bukhari and Muslim), but they did not record it, and I have not found any hidden defect ('illah) in it.

It is narrated from Abdullah bin Shaqiq that Sayyiduna Abu Hurayrah (may Allah be pleased with him) came to Ka'b (al-Ahbar) and asked about him while Ka'b was present in that very gathering. Ka'b asked: What do you want from him? Abu Hurayrah (may Allah be pleased with him) said: "Know that I do not know anyone among the Companions of the Messenger of Allah (peace and blessings be upon him) who has memorised his (peace and blessings be upon him) hadiths better than I." Ka'b replied: "Listen! You will not find anyone who seeks something except that he will one day have his fill of it, except the seeker of knowledge and the seeker of the world." Abu Hurayrah (may Allah be pleased with him) said: "You are indeed Ka'b (who speaks so profoundly); it is for words like these that I came."
This hadith is sahih (authentic) on the condition of the two Shaykhs (Bukhari and Muslim); and a Companion's saying, "I have memorised hadith better than others", is recorded in their Musnads.