Taking risks and facing fears to achieve something good is the definition of bravery.
All brave acts require a proper mix of stupidity and optimism as key ingredients.
It is correct for your friends to warn you away from being brave. Friends want to protect your back and keep you out of pain. But, once you decide to be brave, your friends take a different point of view.
It's more like:If your choice leads to failure, we'll applaud your bravery. If your choice leads to success, we'll applaud your good foresight.
If your choice leads to success, we'll applaud your bravery.
If your choice leads to failure, we'll point out your stupidity.