Today I pre-flighted an aircraft, realized it needed a firmware upgrade on the receiver, performed the update at the field and then failed to re-do the pre-flight afterwards.
If I had done my standard pre-flight, I would have caught the receiver update reseting the stabilizer's channel direction setting, as a result of my failure, I took off with ailerons reversed and crashed immediately after takeoff.
The carnage (and subsequent repair) are documented here: https://temac.ca/smf/index.php?topic=9024.0
The less on learned - if you find and address an issue during pre-flight, restart the preflight.