According to constraint theory, the biggest bottleneck in a person's development is attention. Attention is our most limited resource, even more limited and precious than time.

In fact, the quality and depth of the attention we invest determine the quality of time. However, most people's attention is scattered and fragmented, seemingly unable to fully focus on the here and now.
Pursuing a tenfold growth means we need to focus our attention directly on fewer things, as attention becomes more efficient through focus rather than dispersion.