I too welcome you back Avascar. And I am going to mirror what neopagan just said. If you set the goal of "knowing" and then set the standards beyond human capabilities, you are sort of doomed to be disappointed. By itself, the goal of "knowing" is, in an of itself, sort of beyond our capabilities. Especially when we have to make up what it is we are supposed to know. Anyone can paint a metaphysical picture of the universe and make it seem plausible. But we simply have no info as to whether or not we are a hologram, if there is something more than just this life, or any other easy to imagine alternative to simply being born human and dying that way. Our imaginations can run wild (witness religion) and our hopes are highly customizable (witness new age fanatics) but no answers are yet available, and I don't know how they could be, given the known limits of human awareness in this area. Which is zero.
Kind of wad that goal up like a piece of paper and toss it out. Accept that there are limits. And then delve in to what we can do. Explore the boundaries of human knowledge as we do our best to expand them. Those of us who are not scientists and not doing the exploring have the distinct advantage of being able to marvel, via the Internet and other sources, at the progress being made in dozens of fields. Daily. The universe and the planet we live on are incredible. I love being inundated by the newest findings in physics, astronomy, paleontology, biology, archaeology, chemistry, etc. What fun. Rather than being hunted in the stone age or being enslaved by the Jews or made to huddle in fear before a king, we get to live at a time when our knowledge base, and hence our awareness, is expanding exponentially. We even get to understand what exponential means. Way cool.
The easiest way to be disappointed is to set goals or standards that are unattainable. So forget that "knowing" stuff. That's for the religious, who are all wrong. (I should cut some slack for the Buddhists, who have no god and do a lot of introspection and may be on to something. I can't dismiss all of their insights as quickly as I can the christian attempts. So maybe if you still want to "know", you might start studying buddhism. I don't think you'll find any actual answers, but at least you won't be flinging mud all over reality as you seek answers.)
Life is chock full of the good, the bad and the ugly. And sadly, we aren't all Clint Eastwood. We don't even get to have scripts, like he had. But there is plenty to appreciate, plenty to learn and plenty to do. Take that path.