The only time I had what you would call life-threatening fear was when I was on the Moon. Towards the end of our stay, we got excited and we were going to do the high jump, and I jumped and fell over backwards. That was a scary time, because if the backpack got broken, I would have had it. But everything held together.
The Moon was the most spectacularly beautiful desert you could ever imagine. Unspoilt. Untouched. It had a vibrancy about it and the contrast between it and the black sky was so vivid, it just made this impression of excitement and wonder.
I think a Moon base is not necessary to get to Mars, but I think it will be helpful. It would give you a chance to develop and mature some systems; long duration, deep space stuff; and you're close enough to get some help, via radio from Earth.
Of course, mankind would not have landed on the Moon in 1969, were it not for two things: conquered Nazi rocket technology and post-war anti-Communist paranoia in the United States.
My walk on the moon lasted three days. My walk with God will last forever.