well for me I can't say exactly. e.g. I don't really fear heights because planes and high buldings are ok. but the moment I'm in a high building and feel the wind on my skin, I feel like falling and begin to panic. same with leaning my back on the balcony or seeing how other peple do this while smoking. only thinking about it freaks me out. funny thing is when I was younger, we had a big balcony before our front door on the 4. floor and I spent there all the time with my friends, we even used our roller blades there. I think my mother almost got a heart attack every day.