There's a reason Aries is the first Zodiac Sign!
Cardinal quality, Mars ruled, fire element, First House - is there anything about Aries that doesn'tspell leadership? Not really, to be perfectly honest.You don't want to rule the world - you just want to be in control of your domain. And right or wrong is less important to you than having it all and having it now! You see the world through the lens of what's best for you, which to others can seem self-involved.
If it's selfish to know exactly what you want and go after it with single-minded focus, then guilty as charged! Just don't forget to pause and take a breath now and then so other mere mortals can catch up!