Normally, I'm insane.

we were just as smart then as we are now

we know that she struggles to cope with loss in a healthy way, which is understandable, seeing as death as a concept only became a thing circa 3.5 seconds ago. with Finrod she coped by pivoting straight to action and channelling her grief into a vengeance quest which subsequently stunted the grieving process and left her stewing in a pot of blind rage, BUT with Celeborn it's like she completely buried him within herself, which to me suggests that there could be a certain mystery surrounding the circumstances of his disappearance—disappearance because the word 'death' is never used, so it's not simply a lack of closure that her emotional repression is seeking to substitute, as the grieving process never started in the first place

I doubt Galadriel knows what happened to him any more than we do. the grief isn't stagnant but it can't be turned into action, so she has no other choice but to suppress him entirely, which robs the audience of those memories as well. when he comes crashing back into her life it's like someone's ripping the bandage off a weeping wound, and this new rush of information about Celeborn & their marriage to the audience happens in tandem with Galadriel being forced to process everything for the first time in centuries

after 1515 Attributed to Lucas Cranach the Elder - Catherine of Mecklenburg, Duchess of Saxony