Four-time Formula One world champion Lewis Hamilton said the 2017 season was a key year for him and he worked hard to raise the bar against arch-rival and Ferrari driver Sebastian Vettel.The 32-year-old Hamilton, who races for Mercedes-Amg -- finished the 2017 Formula One season at the top with 363 points ahead of four-time world championship holder Vettel -- who ended the year with 317 marks."My whole mindset was there's a four-time world champion we're competing against," he was quoted as saying by Sky Sports on Saturday. "There's no one else in my view or in my mirrors, it's just him and it's going to take everything to extract everything from the car weekend in, weekend out. "If I don't he will and also he's going to be consistent because he's a four-time world champion so I've got to be even better and try to raise the bar every time," Hamilton added. Hamilton who holds the record for highest pole positions (72) -- said he was assured from the beginning of doing well in the 2017 season."I would say I was more assured of myself this year. I think that comes from a lot of different things. Getting older. Confidence in your work ethic, relationships with the guys you're working with," the 2,610 career points holder said. "We had a bullet-proof plan and structure of how we were doing things, a new resurfaced positive energy in the team that hadn't been there for a while. Plus we were fighting another team so we were super encouraged to go that extra distance," Hamilton added.