It is important to have a strong answer to the question "Why are you doing (insert difficult project)?" It's not just necessary to have an answer, but it should be something that's powerful. Doing something difficult means there will be times where your will-power is tested. You will find yourself being tested by your consciencce - "Why am I doing this?" or "Why am I putting myself through this?" And at times like these I like to have reminders like images, notes, videos, or glimpses of the past-me that decided to embark down this difficult journey.
Writings
