Grief over lost pet triggered by Facebook

[CheckingOutTheQuantocks]

One of my pets died in January this year. It took me months to get to the stage where I wasn't randomly bursting into tears every time I thought about him, and it can still be a bit fragile if I see pictures unexpectedly.

Today would have been his birthday. I opened Facebook this morning and the Memories bit was FULL of pictures of him from last year, the year before, 8 years ago... I suppose I should have stayed off FB but I just forgot what day it was, and that made me feel even worse that I had forgotten about him.

How long is this supposed to take, from anybody else who has been through this?