The author was rejected from joining Y Combinator due to unclear differentiators and not having a cofounder, but they are still interested in applying for the Winter 2020 batch. They attended the Y Combinator Startup School program and found it to be mixed, with useful lectures but hit-or-miss networking opportunities. The author was impressed by the organization and intellectual skills of some YC partners and decided to apply to join the program for its $15k equity-free grant. To prepare for the interview, they worked on their elevator pitch, which explained their company's value proposition and key metrics, such as revenue and growth rate. The actual interview was short and informal, with a focus on showcasing their personality and knowledge of their industry. The author is now weighing the pros and cons of joining Y Combinator, considering factors such as moving to Silicon Valley, giving up equity, and whether their company is ready for this level of funding.