why some people are so smart?

Some are born to be smart, like they inherit their being smart from their parents. Some are acquired like in good school. Some are just patient in studying.

Well it can have a lot of different factors. Someone could have higher intelligence due to genetics. Their parents might do a good job helping them with school. Some schools are better than others so people learn more. I know I'm pretty smart. I have a 136 IQ. Not exactly genius level, but better than average. I have no idea why my IQ is higher than normal. Supposedly the schools I went to are the best in the area, but I think I've learned more outside of school than in school. Maybe people need to have a strong desire to learn to be smart. I love to do my own research about topics that interest me.

Probably because their parents were very smart :D

U mean like stephen hawkings smart?