Valtteri Bottas says something changed "inside his head" after being overshadowed by team-mate Lewis Hamilton last year, with the fired-up Finn unloading on his critics after winning the Australian Grand Prix.
The 29-year-old Mercedes ace, hampered by mechanical problems and bad luck, failed to win a single race in 2018 as the Briton stormed to 11 victories and secured a fifth world title.