How much does to mind remember?

Have you ever wondered if our mind remembered dates and events without us realising, and making us feel a certain way.. And we just can't figure out why we might feel so crap or happy. 

I have been feeling very tired and exhausted the last couple of days, then today I used an app called 'timehop' that goes back onto your Facebook timeline and other social media portals and shows you  said on that day back years.

Today I'm feeling really crappy, and I looked back.. And 2 years today... was my nans funeral.. A funeral I helped to organise, and spoke at.. While also clearing her house with my dad.

What exhuasting and sad time it was for me, my last grand parent, one I had lost contact with for 12 years of my life. A woman I aspire to be..

So does my mind remember that event and is that why I am feeling crappy and a little lost? 

Either way, I will be kind to myself more than usual this week 

Do you ever find yourself feeling like this and then realising something had happened years before on that day? 

Or is it just me being werid?!