Hair gel, lying, the brain

I have worked hard at really listening to others when they are speaking to me. When my kids ask me questions, I try to make sure I understand what it is they are asking and then I help find the answer as soon as I can. Here are some questions that the kids have asked in the past few days:

How does hair gel work? (ok, this is kind of scary - it is essentially liquid plastic!)
When were cats first tamed?
Is colorblindness real?
Which of the Beatles are still alive?
Which member of the Beatles was the oldest when they formed the band?
Have I ever lied?
Does our brain control everything we do?
What does 'catastrophe' mean?
What does 'I do declare' mean?

One more question:  Would you go across this bridge?