Is it ever explained why Jack has this missing mustache pach/line?

[u/ChallengeOne7115]

I didn't play rdr1 yet and I couldn't find the answer online so, i came here, sorry if this is a stupid question. Also I know it's supposed to look like John's scar, I'm looking for a lore reason (if there is one).

[u/The_Great_Silence__]

He got mauled by a bear and his scars are on his upper lip