“...How is that I can still be just as angry 15 years later?...”
Because you’re a human being, and you’re an American.
Because the people that allowed this to happen are still working in the government, and YOUR tax payers are paying their salaries.
Because the wife of the the President who KNEW those animals were in our country is now running for President herself.
Shall I go on?
Remember it was the Bush family at the behest of their Saudi’s masters that got the Bin Laden family out of the U.S.!