Quite right, look at the number of "Rocket Science 101" mistakes NASA has made over the years!
You'd think they couldn't possibly make such a basic mistake, let alone have it get through to a mission state; then yet another mission goes crashing into a planet ... or doesn't fit ... or can't see ... or ....
The bottom line is, don't believe that just because projects have been successful in the past, that fact will necessarily make another project successful in the future.