Ask HN: Indie Hacker, Solopreneur, Entrepreneur Achievement Milestones

For those of you who have jumped off the corporate train (or never got on) - what would you consider the key "achievement" points in your journey? I started thinking through what I would put on such a list but then thought it would make for good discussion here. The achievements obviously vary in difficulty and time required for attainment. Here's my starter list:

* Decided to build a product/service with the intent of releasing it * Learned a new tech stack that I plan to use for the purpose of building my thing * Executed sufficient customer calls to have clarity around potential product/market fit * Public availability / First public customer usage * First dollar generated (ads, subscription, one-time payment, whatever) * Irrationally angry customer feedback via email or twitter * Raman profitability attainment * First paid employee hired * First business development partnership inked * First lawsuit * Sale of company/assets