So that's katakana for you; once you've mastered the 46 basic characters, you're basically done. And if you can cope with voiced syllables, small ya, yu and yos and small tsus in hiragana, they're similarly easy to pick up in katakana.

Probably the biggest challenges, once you've memorized the actual characters themselves, are (1) learning how to read katakana words smoothly and (2) pronouncing katakana words as Japanese words, rather than reverting to the more familiar English pronunciation.

You'd be surprised how many hours I've spent in fast food restaurants, failing to order hamburgers. The Japanese for hamburger is hanbaagaa, not hanbaaga, hanburgaa, hanbaager or even biggu makku. It's not like McDonald's (or makudonarudo) sell much else, but the slightest deviation from the Japanese pronunciation is apparently enough to throw your average fast food clerk completely - so be warned.