The 24-year-old swapped the Premier League for the Championship after helping Burnley secure top-flight football this season.
Stanislas turned down a new contract to stay at Turf Moor but opted to join Bournemouth on a three-year contract.
"It was probably the hardest decision that I have ever had to make. The Premier League is where every player wants to compete," the Englishman told Sky Sports News.
"I could have signed with Burnley again, but it just felt the time was right that I needed to get away and have a fresh start."
Stanislas has made an impressive start under the Cherries, scoring the winner in his second appearance for the club against Brentford.