Thing A is a thing you'd normally never do. You might, from the safety of your comfort zone, consider it, but in the end you never go through with it. But then, one day, you happen to read about thing A in the morning and start to see it in a different light. It's a nice bump in the right direction, but such a bump always eventually wears off because thing A is just too far out of your comfort zone. But then you get another, much larger bump: someone you know and respect also tells you about thing A, and suddenly it's a possibility. One thing leads to another and suddenly you're scheduled to do thing A in the near future. That's all you really need to achieve new things: consecutive bumps that kick you out of your comfort zone.
(No, this post is not about something dodgy!!)