How do you summon courage when something you have to do is scary?

When I was a kid, I was sure our house was haunted. I could hear scary sounds all night long, like thumping. I was sure someone was walking down the hallway a few times. One of my brothers had died at an early age in a motorcycle accident.
One day in the middle of the night I heard the footsteps again, I got out of bed and opened the door, there was nothing there of course, so I walked down the hallway and around the corner to the top of the basement stairs. The house was completely black, and I went down those stairs slowly, waiting for something to grab my feet from underneath. My heart was pounding and I was terrified, but I kept going, down into the basement, feeling my way around the corner where the outside door was, and into the deep dusty black cellar that I knew was full of huge spiders. I got all the way to the end, waited a few minutes trying to see or feel something, and nothing happened so I turned around and went back to my room. Rather quickly as it felt like something was following me, but of course it was all in my head.