I need to learn what?

Hmmm...Try this.

Find the radical in 季.

Find the radical in 香.

Those must not be 子 and 日, because that's just be way too easy (even though the more obvious ones would be 禾 for both).

Likewise, it's hard to guess the radical in 龍.

(Hint: it's the same as the radical in 龘.)

Haha, I get your point -- these all easy if you know the answer, otherwise all impossible if you don't.

For example, 香 and 龍 are trivial (for me) --

they are both radicals in themselves

. But I can only call it trivial because I already knew that. Otherwise, I would have no idea.

I had that feeling about 龍, but I wouldn't have guessed it about 香.

As 香 is a Kangxi rather than simplified radical, I've never paid it much attention (though one would obviously become aware that it is certainly a useful character)...nor it seems has the ABC ECCE in its comparison notes e.g. they point out how 宀 and 穴 are related (in that the latter builds on, or rather extends downwards from, the former, with both always the tops of the characters they are radicals in), but they don't point out how 香 extends 禾, for the obvious reason (once you consult a radical index) that 禾 is primarily a left-side radical (whilst 香 in comparison occurs only three times in the ABC: itself, left, and base, all once each), and to note otherwise (for the sake of simply pointing out that 香 too is a radical) could get students worrying if not completely overextrapolating (unlikely though this might be(?)) into believing that 秃, 秀, 季 (etc) were also radicals somehow.

It would've been nice however if the ABC had at least included 香 itself in the 禾 section (by analogy with 秃, 秀, 季) like simplified dictionaries do, and like the ABC includes 季 in both the 禾 and 子 sections (as opposed to the more hidebound Kangxi tradition of putting 季 in only the 子 section), etc.

wow, believe it or not I did see 小 in there, but I also thought I recognized a modified 月, and 宀, thought at least one of those would be the radical... sheesh