“The finest day i ever had was when tomorrow never came”

Source: Gravity's Rainbow

Source: Tropic of Cancer

"Never Say Goodbye" on It's Alright (I See Rainbows) (1982).
Context: Never say goodbye,
You say tomorrow's another day,
All I know is we're here today. I've got nightmares I could never share with you,
The kind that keeps me up all night.
So hold me tight till the room is light
And tell me that it's all right.

Remarks at a farewell dinner address in New York (20 May 1905), later published in Aequanimitas, and Other Addresses (1910 edition), p. 473.
Context: I have had three personal ideals: One to do the day's work well and not to bother about tomorrow. You may say that is not a satisfactory ideal. It is; and there is not one which the student can carry with him into practice with greater effect. To it more than anything else I owe whatever success I have had — to this power of settling down to the day's work and trying to do it well to the best of my ability, and letting the future take care of itself.
The second ideal has been to act the Golden Rule, as far as in me lay, toward my professional brethren and toward the patients committed to my care.
And the third has been to cultivate such a measure of equanimity as would enable me to bear success with humility, the affection of my friends without pride, and to be ready when the day of sorrow and grief came, to meet it with the courage befitting a man.
What the future has in store for me, I cannot tell — you cannot tell. Nor do I care much, so long as I carry with me, as I shall, the memory of the past you have given me. Nothing can take that away.

Source: Keeping You a Secret

as quoted in a conversation with Max Born about the development of the theory of relativity, by Carl Seelig, Albert Einstein: A Documentary Biography (1956)