וְלֹֽא־זָכַ֧ר שַֽׂר־הַמַּשְׁקִ֛ים אֶת־יוֹסֵ֖ף וַיִּשְׁכָּחֵֽהוּ׃ (פ)
Но главный дворецкий не помнил Иосифа, но забыл его.
Or HaChaim
ופרעה חולם, and Pharaoh had a dream. Inasmuch as the Torah here begins with the introduction of a new episode, we would have expected either the word חלם, or ויחלום, he dreamt, not חולם, he was dreaming. The latter word would only be appropriate if the Torah told us about the continuation of something that we knew had begun previously. Actually, the Torah uses this present tense in this case to show that Pharaoh's dream was a direct continuation of events which had begun when the chief butler and the chief of the bakers had had their dreams. The Torah wanted to show us that even though the chief butler did not want to help Joseph get out of jail, G'd had other means at His disposal to help Joseph get out of jail. It is therefore best to imagine the last verse of the previous chapter and the first verse in this chapter as being continuous, thus: "since the chief butler did not remember Joseph and forgot him Pharaoh had a dream at the end of two years." This eventually forced the chief butler to speak up and mention Joseph as a successful interpreter of dreams.
Sforno
ויצא משה, Moses did not stand on ceremony, using his position to await the arrival of his father-in-law at home, but he went some distance to meet the man in whose house he had received so many favours. We find that Queen Esther, similarly, did not use her elevation to Royalty as an excuse to no longer defer to Mordechai who had raised her. (Esther 2,20 “Esther continued to carry out Mordechai’s instructions as she had done when she lived under his roof.”) Joseph also did not use his exalted position to look down on his brothers. The Chief of the butlers, who had reason to be grateful to Joseph, is an example of ingratitude, as we know from Genesis 40,23, “he did not remember Joseph, in fact he erased him from his memory.”
Da'at Zekenim
כי אם זכרתני אתך....והזכרתני אל פרעה, “so that when you remember me when you are well off, and bring my problem to the attention to Pharaoh, etc;” I heard from my late father of blessed memory that the wording here with the causative mode in the word: והזכרתני, meant that while the cup bearer would personally remember Joseph and his favourable interpretation of his dream; Joseph only asked him to bring him to Pharaoh’s attention through an intermediary.