Lookout is very important, but as others have said it is not infallible
I have to admit, I suspect that like many people my lookout can stop for some other activity, but I conciously try my hardest. To whit anybody who gets the chance should take BRL up on one of his annual organised visits to Farnborough. Heading out of Blackbushe I usually spot several aircraft. However, one look at the Farnborough screen told me that I probably had only seen a fraction of the traffic that was probably visible to me at any one time
But how were the rest of you taught? Not "the others", not "the pilots of today", but YOU?
Whirls, The same as you.