Today I learned the word 石油王(せきゆおう). It's not all that different from how it works in English, I just thought the use of 王(おう) was funny :D
It was also one of those rare cases where I could read the kanji and understand the meaning ("oil king"), but not immediately connect it to the actual concept.
Oh, and I guess I also recently finished all of the N2 Kanji :)
