The suddenness of the thought almost amused him for he suspected this one was not his own. Ever since his ascension to Prime, the Matrix would communicate with him. Not in the way a mech would comm another mech, but similar to how his own imagination matrix would produce ideas inside his helm. Optimus had a difficult time separating his own thoughts from something thought from the matrix- often only being able to distinguish them based on how fantastical or improbable the idea was. And traveling back in time four million years seemed quite fantastical indeed.

the conflict with megatron and the deaths of his autobots in his original timeline causes him to leave d-16 and fellow miners behind to try and fix it all with the high guard. might make it a optimus/some-of-the-high-guard situation. original thought was megop endgame, but there was wicked hatred between op and meg that carried over. optimus doesn't want to interact with d-16- he just has hope that he won't go down the same path. and he doesnt want to face the friends he got killed. bro could heal from these issues tho