The dip

Tim Ferriss wrote about a similar curve in The 4-Hour Chef to describe his progress learning languages:

There's a pattern here. Across language learning, company building, and any kind of creative project, there is a dip. A long period of low motivation, little excitement, and unrewarding challenges. Most people quit during the dip. But if you can manage to not quit, you can make it to the end and reap the rewards.