Roadblocks should be viewed as opportunities for creative maneuvering.
There are many qualities that lead to success, but perseverance is the one that's absolutely essential, because if you give up, failure is a certainty, but no matter what hardships and setbacks you face, if you keep going, you have not failed.
That's why it's important to dream big, but also to dream realistic, and dream righteous, because you need a compelling goal that you truly believe in to propel you through the hard/boring/scary parts you will inevitably have to deal with along the way.
You can craft the most amazing dream, but if it's unrealistic or unjust, deep down in your subconscious you will not believe in it, you'll believe you're wasting your time, even doing harm, and it saps the perseverance to push forward when things get tough. Under those conditions, rather than finding ways to succeed, the odds are very high that you'll find roadblocks big enough to provide a reasonable excuse to quit, as you should, because a dream you don't believe in is not worth pursuing.
The key to success is not training yourself to believe in some wild fantasy you've concocted (that's called making yourself delusional), the key to success is coming up with a big, exciting dream that you can actually believe in, and then never give up working towards it.
Excellent comment. Thank you :)