Period.

"You know I can't remember the last time we kissed
'Cause you never think the last time will be the last time
You always think there'll be more
You think you have forever but you don't"

[Meredith Grey in Grey's Anatomy (S02E17)]

I love that line. Not only because it's from one of the best TV shows but also because it's so very true. How can you memorize a kiss, a hug, a conversation, a phonecall, a chat as being the last one when you believe there'll be many more of them as it occurs? Unless you know you're leaving to never return, you can't. So you're left with a blurry memory to hold on to and probably regrets of not hanging onto everything closer back then. But no matter how often you'll have to go through it, you'll never learn. Because it's not all so sane to live thinking it's the end by every second. So you will always live in the idea of tomorrow will come again, all the same but sometimes it doesn't.

And you'll never be the exact same again.