Learn English – When do you use this expression ‘I am not a fan of ‘

There's nothing grammatically wrong with what you said, and there's nothing stylistically wrong. However, if I were to hear someone say "I have neither a brother nor a sister", I'd expect something like "but I do have a {dog/cat/hamster/gerbil}" next.

I don't know where your English teacher is from, but most of the American- and British-speakers I know would never say anything so formal as ""I have no siblings". Siblings is too formal and scientific-technical a word for most of us. Most native speakers would probably say "I don't have any brothers {and / or[CHOOSE ONE]} sisters".

Everyone has their own idea of what is proper to say and what the proper way to say it in any particular context. There are no stringent rules in English about these types of idiomatic expressions. I, for example, would probably say "I have no brothers or sisters", rather than "I don't have any...". I might, if a little tipsy, say something like "I'm brotherless and sisterless, but not dogless", but that would be a weak attempt at humor.

I'd suggest that "I don't have any brothers or sisters" is the norm for most native speakers, and I recommend that that's the expression to use, but I'm sure that others will chime in here if it isn't for them.

Hindsight is a complex word because of the way it is commonly used.

It is important to understand the phrase "Hindsight is 20/20", because it is the most common usage of the word, and that meaning is almost always implied when the word is used alone. "20/20" is a 'perfect' score on a vision test, and is used here to mean both insight and understanding. Hindsight is 20/20 because events always seem obvious and simple when you reflect on what has already happened. It is also used as a reminder that foresight is difficult and complex.

Because of this, "Hindsight" is often used when discussing an action that should have been taken, especially if the consequences are much more obvious now. For instance, someone undergoing a painful dentist appointment might remark "In hindsight, I should have flossed my teeth."

Your example about Steve Jobs doesn't quite work, for a few reasons.

"Steve Jobs just builds things he believe it's great first, then people will understand his products and his ideas later in a hindsight"

There are three ideas here:

Steve Jobs builds things he believes are great. (Since there are many things, we want to use the plural for believe and it's here.)

People will understand his ideas and products later. (We can group the ideas and products together because they are both "his")

[Steve Jobs' decisions will make sense] in hindsight.

To improve this sentence, we want to make it clear that we are talking about one thing - not things, ideas, and products. It should also be clear that the people who understand later were confused at the beginning.

If we use the definition of "hindsight" to mean something that was only obvious later, we might say:

Steve Jobs made a lot of shocking decisions, which in hindsight were understood to be genius.

By saying his decisions were shocking, we establish why people thought they were not genius.

We could say "only later" instead of "in hindsight" here, and it would mean nearly the same thing. However, there is a slight implication when we use "hindsight" that the answer could not have been known at the time, because we do not share Steve's genius.