Looking for a word or phrase to describe the "scars" left behind from any form of "good time"

Solution 1:

A common idiomatic expression is to pay the piper. This is related to the expression He who pays the piper calls the tune, meaning that there is a price to one's enjoyment or diversion. Or, from Quora:

‘bearing the negative consequence of something that was enjoyable at the time’.

and

don't expect to get something for nothing.

So, for example

Upon waking the day after the party, I knew it was now time to pay the piper.

If you keep that up, you'll be paying the piper tomorrow.

Solution 2:

I would call them battle scars.

Oxford Dictionaries:

Battle-Scarred
ADJECTIVE

Damaged or affected by fighting.
‘a group of battle-scarred veterans’
[figurative] ‘the battle-scarred executives of the technology boom’

Merriam-Webster:

Definition of battle scar

: a scar from a wound suffered in battle

• … a man removed his Yankees cap to show a battle scar — received, he said, when he was a 14-year-old carrying a Kalashnikov in Lebanon's civil war. — Philip Kennicott, Washington Post, 30 Mar. 2005

— often used figuratively

• As forerunners of third-wave American folk music, Amy Ray and Emily Saliers now bear many battle scars from their run-ins with pop culture in the 20 years they've been performing. — Karen Iris Tucker, The Advocate, 30 Mar. 2004

  — battle–scarred adjective

• As battle-scarred gamblers are fond of saying, the only way to be sure you come out ahead is to buy the casino. — Jeffrey Kluger, Time, 1 Aug. 2005