We fail all of the time. Sometimes we fail to stick to a plan, sometimes it’s because our skills don’t allow us to create the thing that’s in our head, and sometimes it’s because taking two steps forward leads to one hasty step back.
But failure is simply an opportunity to do better next time.
Failed to stick to the plan ? Make a better plan. Creative vision not realised ? Practice the base skills until you’re good enough. Taken a step backwards ? Well you’re still one step further forward, and next time, don’t make that same mistake again.
It’s absolutely OK to fail - so long as we don’t make that failure our only try.