What is true Humility?

In Romans 3:23 it says, 'For all have sinned and fall short of the glory of god,' (NKJ). How can we fall short of something that we never had or were never destined to take part in?
The truth is that we are destined to share in God's Glory!
Yes it does say in Isaiah 42:8 'I am the Lord, that is My name; And My glory I will not give to another.' But who are we are we another? or are we part of the body of Christ. (1Cor 12:12 and following verses)
John 17:22, Jesus prayed for us saying to the Father, 'And the glory which you gave Me I have given them, that they may be one just as We are one.'
Why do we find the need to put ourselves down to prove we are humble?
What is true humility? Could it be that we have it wrong?
Moses wrote the first five books of the Bible and he wrote about himself that, 'Now the man Moses was very humble, more than all men who were on the face of the earth,' Numbers 12:3.
Could it be that humility is simply thinking rightly about oneself?
Is it God that puts us down and makes us feel worthless or is it a false religious spirit?
If you were a painter and you created a painting, and someone comes up and criticizes your painting saying it is horrible and the painting is worth nothing. How would this make you feel as the creator of this painting. How do we think God feels when we put ourselves or others down in the name of humility saying that we are nothing or not capable of anything.