There are two different prerequisites to make your creative endeavors successful.
- A planned outlet for your creativity. A recital, a commission, a publishing deadline.
- Faith in your ability to create.
You need both, and in a careful balance. Lean too heavily towards #2 and you will procrastinate and create in a flurry of last-minute panic. Lean to #1 without #2 and you will miss deadlines.
Proceed without #1 and you will never get anything done. Proceed without #2 and you might create once but stop thereafter.
Both of these things expand with time: commissions lead to other commissions, your first novel leads to your second novel. And your successful creation should build faith in your future ability to create.
For young creators, you should start with a deadline and a kernel of faith. Then keep going.