這句歌詞的意思是甚麼？文法是否錯的？

The sentence is correct.

How wonderful life is (main clause)
now (that) you are in the world (adverb clause).

Now that (two words together) is a conjunction meaning "for the reason that".
"Now that" is used as an adverb clause of reason to indicate a situation that arises because something has changed.

"you are in the world" should be interpreted as "you are in my world".

Literally, the sentence means the following.
Life is beautiful since you enter my world.

Life is beautiful since you enter my world(simple present tense here).


Doesn't this sentence sound weird to you, Garlic?


How come "wonderful" means "beautiful" ?

Garlic, what do you think?

2012-11-18 23:53:25 補充：
You wrote:

"Now that" is used as an adverb clause of reason to indicate a situation that arises because something HAS CHANGED.


You also wrote:

Life is beautiful since you enter my world(simple present tense here).

Are you confused with these two tenses, Garlice?

2012-11-18 23:55:25 補充：
Garlic*


Never mind! I am more confused than you are after viewing your WONDERFUL answers. lol

2012-11-19 00:00:00 補充：
知D不知D，不知為不知，是不知也。

生命如此璀璨，只因與你同在。
from the song in the movie "Moulin Rouge".

Ignore "is now","are"
The sentence:-How about the wonderful life you go for in the world?