Those who say, 'It can't be done,' are usually interrupted by others doing it.

Those who say it can't be done are usually interrupted by others doing it.

People who say it cannot be done should not interrupt those who are doing it.

When you think about it, if the fittest always won, all forests should be completely homogeneous. One species should supplant all others as the most superior competitor. But it doesn't happen that way. Nor does it happen that way in the marketplace.

The world is moving so fast these days that the one who says it can't be done is generally interrupted by someone doing it.

The world is moving so fast these days that the man who says it can't be done is generally interrupted by someone doing it.