Forgot vs have forgotten anniversary

Question

My understanding of present perfect is basically something that has the possibility of happening more times,

The author has written 3 books (he could write more books)

The author wrote 3 books (he can't write more books because he died)

But with the verb forget I get a little confused sometimes.

Context: I just got home from work my wife prepared something for our anniversary but I didn't prepare anything because I forgot the anniversary, after realizing that what could I say to her?

I read a comment recently that says both of the following phrases are correct:

1. Sorry, I've forgotten our anniversary

2. Sorry, I forgot our anniversary

How could the present perfect be correct if, for me to talk about the anniversary in the present, I would have to remember it in the first place? Thus the forgetfulness is now completely in the past.

I get that there's a consequence on the present time by me forgetting the anniversary.

Are those two phrases correct and make sense in this context? In my head only 2 could make sense, but since I'm not a native speaker I cannot say that for sure.

Could this phrase be an option?

Sorry, I forgot our anniversary and I haven't prepared anything but I can still fix this let's go to that restaurant you love.

Answer 1

My understanding of present perfect is basically something that has the possibility of happening more times,

This is an erroneous understanding: "My father has died." This is never going to happen again.

The present perfect appears in statements and questions that refer to the state of things at the moment before it is spoken:

"Have you cleaned your shoes?" / "You have cleaned your shoes."

I read a comment recently that says both of the following phrases are correct:

Sorry, I've forgotten our anniversary.

Sorry, I forgot our anniversary.

They are, indeed both correct.

The main difference between the present perfect and the simple past is that the present perfect cannot accept a phrase or clause that expresses a definite time:

*Sorry, I've forgotten our anniversary yesterday.

Sorry, I forgot our anniversary yesterday.