I have mentally overcome situations most of you would be terrified to ever attempt: heights fire needles spiders snakes angry monkeys being shot being hit by a car going blind - you name it I have been in a situation where I have had to mentally overcome my inherent fears to do my job.
Time is a sort of river of passing events and strong is its current no sooner is a thing brought to sight than it is swept by and another takes its place and this too will be swept away.