Okay five parts in the attack on titan manga remain unanswered .Here are the for parts in the attack on  Titan manga:

1)In the 1st chapter /episode in the animal the ttile of the episode or chapter is called to you in 2000 years.Some people say that it doesn't mean anything then why didn't he choose sth else then?That means that there is a meaning befind of it,especially this title because the are thousands of other titles that I can come up with for the 1st episode or chapter.

2)In the very 1st part of the 1st chapter of the manga,we can a grown Mikasa saying see you later Eren happily. What does this means?

3)Zeke said to Reiner and Bertholt that he will put an end to the curse history .Which is St mysterious ,isn't it?

4)When Zeke talked to eren he said to Eren that he will come andown save him someday. What does this mean hmm? 

5)Eren Kruger said as he was going to inject Grisha Jeager ,Erens dad ,the serum to become a titan shifter that he has to save Armin,Mikasa and the others.When Grisha asked him who are they ,Kruger wondered whose are those memories .

TELL ME IN THE COMMENTS IF YOU WANT ME TO TELL YOU STRONG THEORIES ABOUT THEM.