은/는 and 에게 are not interchangeable in most cases. They have distinct uses. 은/는 is used much more broadly as a topic marker. It introduces something to set the basis for what follows. 에게 has a more narrowly defined sense of "to" or "for", as the object of an action (친구에게 책을 선물했다), or the person or thing some fact or condition relates to (나에게 이 경험은 값진 것이었다). In more details, - 나는 그리스 신화가 좋다. 나는 sets the basis, like "as for me", for the specifics 신화가 좋다. - 너는 그리스 신화가 좋니? = Do you like Greek myths? In these sentences, the detail part after 는 is an intrinsic quality or fact belonging to 나/너. Similar structure may be used with 에게, but in this case the detail is something that merely relates to the subject in some way, not wholly pertaining or belonging as in the case of 은/는. - 나에게 그리스 신화가 좋다 (BAD) - unnatural and confusing, like "Greek myths are good to me"). - 나에게 그리스 신화는 재미있다 / 깊은 의미가 있다 (OK) - Greek myths are interesting / deeply meaningful TO ME. (The grammar is dependent on the adjective and the person(first or third) too, but this is a rather long subject). Another example: - 나는 기억력이 좋다 = As for me, I have a good memory. (기억력이 좋다 is an attribute of 나) - 나에게 기억력이 좋다 (BAD). - 나에게 [좋은 기억력은/기억력이란 부러운 것이다] = [Good memory is an enviable thing] for me. - 좋은 기억력은 나에게는 부러운 것이다 = (same)

Ohh I understand now! Thank you very much!

너는 그리스 신화가 좋니?(good sentence) 너에게 그리스 신화가 좋니?(Not good ) you know We use 이/은/는/가 for suffix next to subject in sentence. ex) 나는(suffix) 너는(suffix) 우리는(suffix) 사람은(suffix) and 에게 is for object's suffix. ex) My(나의) father(아버지가_가 suffix for subject in sentence) tells us(우리에게_에게 suffix for indirect object in sentence) interesting stories.(재미 있는 이야기를 _를 suffix for direct object in sentence)