If you aren't making mistakes, you aren't reaching far enough. Of course, when we are talking about something like making a decision on dinner, it's one thing, but when it is something where your career is on the line, it's a whole other ballgame.
The problem is though, that sometimes we have to reach out of that comfort zone and stretch, or else we aren't going to have any new experiences, and new experiences are what it takes to truly learn. From each new experience, other opportunities open up and provide us again another chance to learn. It's a never ending cycle if done right.
If you bring a potted plant home and leave it in the pot, it'll grow for a while, but ultimately, it will only grow as big as the root system can manage, and in the confines of a small pot, that's not likely to be far. But put that plant in the ground, give it the right amount of care, and it will do well and thrive. Likewise, though, transplant it into the ground and abandon it, and likely it won't.
Personal growth is necessary for success. It goes without saying that no one is simply born a success, unless your parents happen to grace the tabloid pages regularly, and it should go without saying, that's not success. Success and fame aren't necessarily the same; success requires achievement, and achievement requires effort.
But even the most effort in the wrong place or at the wrong time can be wasted. If you took that same plant, and transplanted it into the ground in say, Antarctica, all the hard work, fertilizer, and love isn't going to keep that plant alive. You have to seek opportunities to put your efforts into, do them with passion, and if the time is right and the conditions right, success will bloom.
When you give everything your best and things don't go right, consider that sometimes the timing isn't right or perhaps you needed another factor to work that you hadn't considered. But even the most talented gardener will tell you, you can't just give up because one of your projects went bad. You have to look hard at what went wrong, learn from it, and make the changes to improve for the next time.