Let's see if I can't answer these questions, whether they're serious or just brain farts...
-I'm not sure if I would NOTICE, but things would definitely change. Never doubt the importance of people and things, no matter how small. We can all make a difference, we all affect the chain of life.
-...Come again? If you're talking about the ultimate understanding of everything, sounds like something only a god can do. Not sure a mortal could do that. We'll never understand everything in life. All we can do is find out what works best for us, hold fast to that, and change what needs to be changed if it is keeping us from bettering ourselves.
-You know, I'd like to think that everyone has a moment like that in their lives. Even if we come from the worst conditions that no one should have to be born into/grow up in, I'd like to think we all experience a moment of perfect happiness and bliss that we'll always carry with us through our lives. When it happens, we don't know if we're experiencing it. But that's just one of the beautiful mysteries of life, and it's just one of the reasons to just keep marching forward and living life to the absolute fullest. You never know when you'll experience your own slice of heaven-on-earth for the first, second, or third time. As long as there is a tomorrow, it can happen any time.
...I like lettuce and cheese in my burger.