Yes Man (2008)

Carl Allen is at a standstill. No future - until the day he enrolls into a personal development program based on a very simple idea: say yes to everything. Carl discovers with amazement the magical power of "Yes", and sees his professional and romantic life turned upside down overnight: an unexpected promotion and a new girlfriend. But he'll soon discover that better can be good's enemy, and that not all opportunities should be taken.—Happy_Evil_Dude