So Shanks reached a bounty of 1 billion in less than 2 years and became a Yonko 8 years later
But Oda made a big mistake here. Oda had previously shown Shanks at 20 years old traveling to yassup's island
Am I wrong or did Oda make such a big mistake?
Full Shanks timeline:
39 years ago = born on GV and taken by Roger's crew as a baby
25 years ago = Roger's crew finds OP (without Shanks) and then disband (with Shanks)
24 years ago = Roger is executed, Shanks asks Buggy to join his crew
22 years ago = Shanks asks Yasopp in East Blue to join his crew
19 years ago = Shanks' crew adopts baby Uta
(NOT CANON)
18-15 years ago = Shanks' left eye gets scarred by BB, also has many duels with Mihawk during this time
15 years ago = Shanks goes to Marijua, covers his injured left eye, becomes Holy Knight, gets Imu level 1 Tattoo, and frees Fisher Tiger
14 years ago = Shanks leaves Marijua, goes to Elbaf and meets Scopper Gaban
(same year where Harald dies)
13 years ago = Shanks' crew attack CP9 ship, beat Who's Who, and steal Gomu Gomu (Nika) fruit
12 years ago = Shanks' crew is framed for destruction of Uta's island and he gets 1 billion bounty
(NOT CANON)
12 years ago = Shanks' crew goes to East Blue, meets Luffy, saves him, loses his arm (with tattoo) and gives him his hat
6 years ago = Shanks defeats and captures Loki, and becomes Yonko in same year