Irregular kanji readings ?
I was always eager to learn this language, the last 2 months I would spend in learning kanji, their meanings and their pronunciation, during pauses at work and during bus rides, so basically almost each minute I could spend on learning kanji I would do so, and I managed to learn about 80 kanjis along with their readings. Just to get a kanji punch into the face when I started the active phase of my learning process. I stumbled upon several kanjis whose reading does not match up with the onyomi and kunyomi readings I already learned. Like: 今日 this kanji for example. When I first saw this kanji I could already grasp the meaning behind it, 今 means "Now", and 日 can stand for "Day", thus 今日 means "today". But the pronunciation is neither "konnichi" nor "kinjitsu" or "imaka" and so on, no the actually reading was "kyou". Are there many instances like this one in the japanese language ? I feel like as if though japanese just wants to tell me: "come on, give up, are you mad". Just when I start to think OK this is going well, I am getting the hang of it, japanese comes with another surprise up its sleeve for me
Yes, there are a lot of cases like this one.
This is one of the reasons why I think learning individual kanji like that is a bad idea, I prefer to learn vocabulary and the kanji associated with it alongside.
I started learning Japanese about 4 months ago and without any specific kanji study I now know around 350-400 of them (meaning that I'm able to recognize them and their general meanings, write them but only know the readings associated to the vocabulary I learned). I expect to know at least a thousand after a year of studying in the same way... and it feels so much better than systematic kanji study.
If you really want to study kanji systematically, you should probably only learn their main meaning, that's what a lot of people who want to study kanji systematically do (which again, I, personally, do not recommend).
There is no point in learning all the kunyomi and onyomi readings of the jouyou kanji, simply because often you still wouldn't know which one to choose if you met them in an unknown compound and anyway it would be quite overwhelming.
Yeah, there are quite a few of these cases. My advice is to not be so strict with the readings; they're nice to know (especially when you come across a word you don't know and are trying to pronounce it), but don't treat them as gospel. Try to focus more on the meaning. For example, "adult" is 大人, but it's read as おとな, not だいじん or だいひと. But, the kanji mean "big person," so you just associate the meaning of the kanji with the word without thinking about readings. I hope this helps!
Actually, "konnichi" is another reading for this word, though "kyou" is bay far the most frequent. Anothe rway to look at multiple-kanji words like this is that when the Japanese had a single word for a concept that in Chinese was expressed with two characters, they borrowed the two-character word and put a Japanese reading on it. Quite a few of the words for relative days and times are like this: 今日 kyou, 昨日 kinou, 明日 ashita/asu, 明後日 asatte, 一昨日 ototoi, and many others. Don't think of the kanji as individual phonetic units.
A famous example in English is "half" written "1/2". Someone learning English would throw up their hands just like someone learning Japanese would with 今日.