No memory tears after completing mission

I have been playing the league since launch averaging a 3-4 hours per day 3-4 days each week. Since completing the threads of the originators questline I have not seen a single memory tear.

I am not sure how many maps I have run however I am level 97. If I had come across 1 by now I would of just said I am unlucky but to have seen none seems impossible.

I am using the nodes at the top of the atlas passive tree, have completed all other content (outside of ubers) and have encountered a number of reflecting mists and seers which I believe have a similar appearance rate.

I found a few in various tiers of maps. Haven't got any of the nodes allocated in the Atlas tree. RNG most likely.

Are you sure you dont already have 1 queued up? Go talk to Eagon and check, if he has one available to run, then you wont see another until you run it.