Public speaking as the most common fear is not something I ever experience. It's basically my job!

As a youngster the threat of a tornado really would get to me. Along with all the other kid fears (killer Bees).

As a teen, I experienced true propaganda fear as politicians had me convinced that the commies were going to make their way north thru Central America and on to us.

Nowadays, not really heights but more the edges that gets my tummy tinglin'.

Maybe a genetically engineered PETA weapon?

I still hate fire. Being burned alive would be my biggest fear.

I've had the same experience Steven. In my early 20s I frequently worked at heights twice that of my house - unnerving initially but I got used to it. 20 years since and I recently had to work near my roof gutter. 20 foot up a ladder looks an awful long way down now. Heights are no longer in my comfort zone. 

Not sure I'd call it a fear though. 

For me that would be crocodiles. I live in the UK so it's totally irrational. 

Just thinking about a shark when I'm swimming in the sea can create a frisson of mini-panic -- and everywhere I've lived has water colder than sharks tend to like!

I swam at Manly in Sydney and got buffeted around by the waves for a while, but could only do a few minutes before I thought this isn't worth it.

Even with the shark nets at Bondi, I didn't feel safe. Great barrier reef was OK, because the big sharks aren't supposed to frequent those waters and snorkelling somehow made it better.

Similar thing at Miami Beach to Manly -- popped in for a few minutes and then just thought it wasn't worth it.

The Med is OK. Bournemouth Beach is OK. The Northumberland strait is OK. But as I say, I can still scare myself with a little shark thinking.