[nuancebydefault]

In the first spacex rocket Musk thought that it was a good idea to not install baffles. He learned from experience that they are indeed needed.

[m4rtink]

I remember a very similar anecdote about Von Braun & the early Juno/Jupiter rockets - with someone pointing out issues with sloshing on a press conference & Von Braun brushing it off as insignificant.

Then the next launch crashed due to slosh induced oscillation - and the one rocket after that had anti-slosh baffles. ;-)