My daughter (5 y.o.) and I watched a replay of the landing the other night and she asked why people were crying and I told her that these a lot of these people have invested 8 years in this one thing and every single person had to have everything they worked on perfect or all of it would fail.
People don’t realize that with Spirit and Opportunity they could just airbag down the smaller rovers, Curiosity is a small car. Even the idea of a skycrane was insane. I am very glad I stayed up late to watch it live, really have not felt that sense of wonder in a long long time.
This video is excellent and if anything, is under-dramatic.