The passage below from the Watchtower Society's bible is deliberately misquoted. Watch for it.
● Ps 146:3-4 . . Do not put your trust in nobles, nor in the son of earthling man, to whom no salvation belongs. His spirit goes out, he goes back to his ground; in that day he loses awareness.
The actual passage says "his thoughts do perish".
The Hebrew word for "thoughts" in that passage is 'eshtonah (esh-to naw') which means thinking rather than awareness.
Unfortunately, Ps 146:4 is the only place in the entire Old Testament where 'eshtonah appears so we can't compare its uses in other contexts.
According to Webster's the word "thinking" is ambiguous with quite a variety of meanings to choose from; including, but not limited to: concerns, anticipations, conceptions, opinions, imaginations, visualizations, ideas, epiphanies, plans, schemes, fantasies, arguments, aspirations, deliberations, and the like.
For the rich man in Jesus' parable at Luke 12:16-20; I would choose ideas, plans, and schemes.
For example: consider all those people who perished in the World Trade Center, and in the Japan and Indonesia tsunamis, and the Haiti earthquake. None of them woke that day planning on it being their last on earth. No, on the contrary; they had people to see, places to go, and things to do: but before the day ended; whatever was on their itinerary lost its importance-- their priorities went right out the window and became no more significant than green cheese on the moon.
All their plans, their dreams, their schedules, their appointments, their schemes, their problems, their ambitions, their loves, and their aspirations went right down the tubes as they were suddenly confronted with a whole new reality to cope with.
So then, an alternative to the Watchtower Society's interpretation is that people don't cease to exist when they die, nor do they lose awareness; no, Ps 146:3-4 only means that whatever was on their minds before they passed away is now null and void.
Take for example Michael Jackson. While working on a new world tour, Jackson died in his sleep. As a result; his tour wrapped on the spot.
When my eldest nephew was paroled from prison, he quit drinking, and began going to college with the goal towards becoming a counselor. For 2½ years all went well. His parole officer was happy, and he was on track and getting good grades. My nephew's future looked assured. And then on the morning of Sept 25, 2015, he dropped dead to the floor of natural causes.
My nephew's passing was a terrible disappointment to everybody; but actually we all kind of expected it. He was grossly overweight, had high blood pressure and high cholesterol, rarely exercised, and smoked. But the point is; my nephew's dream ended just as abruptly as flipping a light switch. And all of our hopes for his success ended the same way, viz: our thoughts perished right along with his.
Death is the mortal enemy of human ambitions. It often casts its long shadow when they set about planning their lives. The Scottish poet Robert Burns noticed that life sometimes throws a curve ball that makes all your careful preparations strike out instead of getting you on base.
He was working one day plowing in the field and uprooted a mouse's underground nest who was all set for the oncoming winter. The mouse had picked a fallow field as the site for its winter retreat thinking it would be safe and snug; unmolested during the cold. But it didn't (or maybe we should say it couldn't) know the workings of powers higher than itself-- in this case, farmers and their machinery.
Mousie, you are not alone in proving foresight may be vain.
The best laid schemes of mice and men go often askew,
And leave us naught but grief and pain for promised joy.