what is the nuancee's difference of each sentences?? "i think him vs i think of him vs i think about him. "preposition of vs about

i'm not a english native speaker.so i usually don't know the difference of meaning among words.

i want to know the nuancee of three sentences below in detail.

1. i thought him 2. i thought about him 3. i thought of him.


of course, i tried to understand the differencen of nuancee of them.but though i read the meaning of them , i can't understand.


naver english-englsih dictionary

think about somebody/something

1. to have ideas or images in your mind; to remember somebody/something

2. ( think of somebody/something) to consider somebody/something

When you think about ideas or problems, you make a mental effort to consider them.
She closed her eyes for a moment, trying to think

think of somebody/something
1. to have an image or idea of a particular person or thing in your mind

If you think of someone,
you show consideration for them and pay attention to their needs.

I'm only thinking of you. (??:Collins)

I can't think of her face.

question2.

that's very nice of you / i'm pround of you - these sentenses are right. but

that's very nice about you / i'm pround about you. -it's wrong, right?

i know the difference of nuancee of them in my heart(emotion)
but i can't explain it rationally( logically)

Could you explain me through the particular situation??

at last, Waht i really want to know is the preposition's properties of between " of " and "about".

thanks for your reading.



that's very nice about you i'm pround about you.
(non English text removed; please post in English only)