Belichick has guided his side to three Super Bowl wins during his time in New England but the last of those came in the 2004 season.
He told reporters: "Every year is different. Every year is a great challenge, a great opportunity. Every time it comes around, it's nice to be able to go up to the plate for a turn at bat.
"Every part of it, whether it's assembling a team, working with new players, working with veteran players that are experienced and extremely talented at the highest level, game-planning, scouting, preparation, practice, games -- I enjoy all of it."
New England open their season at the Buffalo Bills on Sunday.