People like nice guy, but often an aggressive guy gets what he wants.
In a social setting, no one likes a guy who picks a good looking girl but then moves on quickly to the next prettier girl who is just catching his eyes. A nice guy would gracefully wait for his turn, which might never come.
Same in the business world or in a work environment.
A smart guy is someone who knows what he wants while behaves nicely in his approach or execution. It takes skills or experiences to get what he wants, as quickly and gracefully as possible.
