Help required understanding Yugas

[Brahmos 0]

Hi,

 

Before I start, let me just say I am wonderstruck by the 4 yugas, how they explain a lot and karma too, in our religion. I have a gap in my knowledge regarding the 4 Yugas, which is, how/why did the people of each Yuga now know what was going to happen regarding the avatars of Vishnu.

 

I can understand we are in ignorance now because we are in the Kali Yuga, But for example in the Treta and Dvarpa yugas, the people were more spiritual and knew of the scriptures and past and cycles more than now, why did they not know Rama and Krishna was to come and play out their same leelas time and again? Why did they not recognise them? Was it because of ignorance, does the Mahabharat/Gita texts get wiped out by the Kalki avatar at the end of each 4 yuga cycle? And the Vedas become of importance again, until each avatar comes? What did people kno of upcoming avatars and yugas?

 

Thanks!