Success, in anything, requires a degree of delusion. You don't want to be so delusional that your friends and family attempt to check you into a psych ward. But, your delusion should cause them to consider sitting you down for an intervention.

It's important to remember that most of the people who inhabit this planet are fairly rational. This is a good thing. It's to humanity's benefit. If everybody who existed on this strange space rock were completely out of their gourd, we'd have blown ourselves up decades ago.

With that said, if you're an ambitious individual, you must constantly remind yourself that you live in a highly rational world. Those who care about you will attempt to force their rationality upon you. This is an act of love. They don't want to see you get hurt. They don't want to see you go broke. They don't want to see you fail. But, you must ignore them. No matter how much you love them and respect them, you must ignore them.

For rational thinking achieves rational outcomes.