The best in the world don’t often have to look for their ball – they hit it straighter than most and usually have a good number of marshals and spectators to see where the ball landed. So Bryson probably has a good excuse for being a little hazy on the lost ball rule.
If it is known or virtually certain that your ball is in a penalty area or an abnormal course condition you don’t need to find it, but otherwise if it isn’t located within 3 minutes it is indeed lost!
Golf Rules Guru 