"Fake It Till You Make It" — Elizabeth Holmes

Elizabeth Holmes's 'fake it till you make it' mantra led to an 11-year prison sentence for fraud at Theranos, a far more disastrous outcome than even the average business failure. This advice carries a catastrophic 90% startup failure rate within three years—50% higher than the typical tech company's failure rate and drastically worse than the outcome of following #9's advice, which at least keeps you out of prison. Data shows that Holmes raised $945 million based on fabricated results, yet the company was valued at $9 billion before collapsing to zero.