Consumer unit - If i need to change a light pendant Will turning off the one switch be enough?

[morqthana]

It substantially reduces the risk of inadvertent re-energisation, either from someone who doesn't understand why the switch is off, or from someone or something bumping into the switch.

I assumed, given the name and nature of this site that TAMD8389 is a DIYer, and people don't tend to live in houses so large, and so full of random people who can't be told what's going on, that a switch would get turned on by mistake.

Or by accident by any of these hordes of random strangers blundering about.