That's because those wispy, hazy and long trailing cloud formations are MAN-MADE. Whether created for sinister reasons, as chemtrails, or as artificial clouds for rain seeding purposes, these types of cloud formations were not in the skies pre-1985. Or if they were, they were few and far between.
This basically means, that anyone who is born post-1985, has been taking the wispy, hazy and long trailing cloud formations as being natural cloud formations; and won't see them as anything unusual as they've grown up with them. Their comprehension chemtrails and deliberate geoengineering is not likely to be at all positive; they are going to be very skeptical of it all. They are not likely to see anything untoward, and are not going to buy the 'conspiracy' stories at all. Even when faced with proof, their perceptions will not see the dangers, because their mind cannot see what it has not been programmed to see.
The problem we, as the human race, are going to have is when all those who remember skies free from chemtrails, have perished, and there is nobody around who can remember the clear skies, there will be no reference point to how things should be. It will be accepted fact that those clouds are part of the natural cycles. And nobody will know otherwise.
