Running Past Mental Barriers

On May 6, 1954, Roger Bannister became the first man to run a mile in under four minutes. Although it is a myth that physiologists considered the barrier physically impossible, what is interesting to consider is this: By 1957 another 16 runners had also accomplished the feat.
In other words, it is now evident that the sub 4-minute threshold was a mental barrier to a great many runners.
The story is worth keeping in mind as you struggle against certain barriers. Are they real or just mental. If the latter, the only other question you need to ask yourself is whether you will be the one to unlearn the barrier or are you content to wait for someone else to do it?
The choice, of course, is yours but know this: Few people remember the second person to break a barrier. (In case you're wondering, Australian John Landy was the second man to run a sub 4-minute mile.)