A "stark realization" means to suddenly and clearly understand something, often a truth or a fact, with a strong and noticeable impact. Full definition
In a way, Lee captures the subtle beauty of former times and of people being caught in the past, against the grain and stark realization of a newly formed world. (goodreads.com)
Melanie faces a lot of stark realizations about the real world as the movie progresses. (mediamikes.com)
As such, that extreme challenge of «stopping to think» brings to surface a mind - bending stark realization that, consummately, planet Earth is extraordinarily precious, almost beyond imagination, a vibrant blue sparkling jewel in the cosmos, truly an eye - moistening reflection. (counterpunch.org)