The examples are different but the definition itself is plain. Is it jumping off a high cliff because no one else will? Well, you're half right. Not the jumping from a cliff (unless you're speaking metaphorically of course). Meaning more along the lines of doing something that terries you. Something that no one is willing to do, not even yourself sometimes.

It takes courage to go against popular beliefs, society standards, and even family social upbringing. To dress however you want and do what you want when everyone is telling you not to. At first, everyone will say it's impossible and pointless. That what you are trying to achieve will never be reality such as becoming a voice on Youtube or a dentist even. They begin to push you down and when you finally reach your goal, everyone talks about always knew you could do it.

Opinions from others can, to a certain degree, affect the way you live but your life should never be defined by them.

Be different. Be happy. In this cold place, we need more and more people with courage. There will never be a time in this world that we will ever need a lack of it. Even if it's a small task that you may feel isn't worth it. Small moments to you could mean so much to someone else. If it scares you - confront it. I know that it is easier said than done. Imagine your emotion as excitement instead of fear. They both come with a huge amount of anxiety but the outcome is different on how you chose to act towards the situation.

Tell that person you like them. Take that class you think you might fail. Remember though: it's not just having the courage to begin, but you should also have the courage to keep going.