Words and phrases in katakana may appear to be easily recognizable to non-native speakers of Japanese, but they are often fiendishly difficult. This generally comes as a surprise to Japanese, who naturally assume that we can understand katakana words readily, seeing as many of them originated in foreign languages.
It took me years before I could pronounce my own name in Japanese: Parubasu. In the next life, I am going to be born without a p, l, v and r in my name. I'll take a simple name such as Oak, so everybody can call me Oku-san and refer to my wife as Oku-san no okusan.
Just because words are borrowed does not mean they necessarily have the same meaning. Direct borrowings are called "cognates"; and when the meaning differs, we refer to them as faux amis, French for "false friends."