Preposition "To" to denote the cause of emotion
ex.
① I was surprised to know the news.
② I'm sorry to be late.
③ It's good to see you.

I've ever read the "to"s used in sentences like these denote the cause of emotion, you know, why surprised, why feeling sorry, and why feeling good. But as a learner of English, I do not understand the nuance or logic to use "to" to refer to a kind of past event (=cause), even though "to" usually has future image. I'd appreciate if you could fix my somehow wrong impression.
Thanks.

Question

Preposition "To" to denote the cause of emotion
ex.
① I was surprised to know the news.
② I'm sorry to be late.
③ It's good to see you.

I've ever read the "to"s used in sentences like these denote the cause of emotion, you know, why surprised, why feeling sorry, and why feeling good. But as a learner of English, I do not understand the nuance or logic to use "to" to refer to a kind of past event (=cause), even though "to" usually has future image. I'd appreciate if you could fix my somehow wrong impression.
Thanks.

Answer

I'm sorry to hear that you don't understand.

You said "even though 'to' usually has future image"

I don't understand why you think that "to" has some relation to the future. "To" does not mean the future. It is just a preposition. It can be used in many different sentence structures.

Maybe you are thinking of the structure "to be going to do something". For example, "I am going TO learn English today" is talking about the future.

However, in that example, it is the whole sentence that is talking about the future. The individual word "to" does not have any meaning. It has a function, but no meaning.

I will try and explain the sentences to you another way (without using "to").

"I was surprised to hear the news" means "I was surprised when I heard the news".
"I'm sorry to be late" means "I'm sorry that I am late".
"It's good to see you" means "it's good that you are here and I can see you".

Answer

Hello,

The preposition 'to' has many usages.

I hope this explanation helps.
https://www.thoughtco.com/how-to-use-preposition-to-1211798