learn about Kanji

In the beginning, Chinese dudes wrote pictographs - pictures that looked like the things they represented. The drawback was that writing a paragraph took as much time as drawing a comic book, because IT WAS drawing a comic book! So they (Who? Sages, motherfucker, sages! Who else?) simplified the pictographs into what we now call Kanji. How?
Step one: They chose 200 or so RADICALS as their building blocks.
Step 2:
Any pictograph that was too hard, they said, “OK, what radical does the top part most closely resemble? Swap 'em! What radical does the left part most closely resemble? Swap 'em!” and so on.

For example, the old, complicated kanji for country is　國 . And the current kanji for country is 国。

Now, from the foreigner's point of view, this change is retarded in two ways.

1) the radical that was swapped into the center of the new version means " jewel." (a jewel in a box? What does that have to do with a country?)

2 ) the simplified 国   looks almost the same as the kanji for treasure;　宝 . (more confusion!)

But try looking at it from the point of view of the sages: they didn't have computers, they got bad arthritis, and they had to draw these crazy hard pictographs all damn day. So one of the sages, in his wisdom, said, “"OK, fuck this! Can't we swap the center bit for a simpler radical?” "And the other sage replied, “"Dood, if you drink enough sake,  the center bit looks kind of like 　玉 .”"
And the first sage was like, “"Man you are just high as hell, but it's late and I got mad poems to write about seasons and shit, so yeah, let's just say 國 　 is now officially 国 and call it a day.”"

So that is how that went down.

yes, I read kanjidamage too. but

So they (Who? Sages, motherfucker, sages! Who else?) simplified the pictographs into what we now call Kanji.

Except it's called hanzi. Kanji - japanese shit.
Hanzi - chinese shit. Hangul - korean shit.