It would change my career and retirement planning quite a bit. I'd retire early. I would forget having kids, since I wouldn't be around to support them after their mid-teens.

Think about it from the flip side: If you knew you were going to live to age 200 in good health, wouldn't you retire later? Maybe you'd spend more time gallivanting around the world like a recent college grad. Maybe you would wait longer to settle down and have children. Any deviation from the current typical life-span should definitely change your behavior.