Board Thread:Whoniverse Discussion/@comment-24121492-20150919193757/@comment-24121492-20150923132750

Yea, you're missunderstand.

The Doctor created Davros. So in order for the Daleks to have existed prior to this episode, it means the meeting between The Doctor and Young Davros ALWAYS happened(it wasn't the Doctor just messing with time). So if it always happened, why did Davros never mention it until now? I mean yea, the idea wasn't thought of, but there has to be an in-universe explanation.

And DWTV said that it's explained why it wasn't mentioned till now.