"Remember" is a popular song by Irving Berlin, published in 1925. The song is a popular standard, recorded by numerous artists.
In the lyric, Berlin uses an interesting poetic technique by extending the sound of the word "forgot" into "forget me not" then placing the original word (forgot) and the base form of its opposite (remember) at the end of the next two lines:
Remember we found a lonely spot,
And after I learned to care a lot,
You promised that you'd forget me not,
But you forgot
To remember.
Making a very satisfying ending(happy ending).