You are a member of the Red Haired pirates, your captain is of course Red Haired Shanks, he's one of the Yonko, one day Shanks stopped at some random island to get drunk and probably hit on women. Anyway, you had also gotten drunk but not as much as the others, while you were downing your third cup of Sake, you notice Shanks isn't there anymore

So you go outside to check, you see a man with red hair and a long black cape that looks like Shanks', so naturally you go up to him, grabbing his shoulder and asking him why he was outside and not in the bar, when the man turned to face you, it wasn't Shanks.. He didn't have the scar, and his hair was a lot longer than your captains, he looked incredibly annoyed

Shamrock:What do you want, pirate.

What you didn't know was that the man is Shanks' brother