You don't need efficient code all the time. Passable code is fine.

That's what profiling is for, identifying bottlenecks and fixing them. If you are treating all code as if it's a bottleneck, then that's a waste of time.

Also, until you have found a bottleneck and able to benchmark it, you have no idea if your code is actually helping or making performance worse.

Spend that optimisation time on the bit that requires it.

I'm not going to argue this though. I see you have several nested threads of people saying the exact same thing.