Since writing his book Outliers, it has been widely written and commonly accepted that Malcolm Gladwell is right with his assertion that you have to invest a lot of time into becoming brilliant at anything. (He personally suggests 10,000 hours).
Compare this with specialists, experts, gurus and other self appointed consultants who approach you through various platforms claiming either to be an expert or to be able to quickly get you to speed and operating like an expert.
Be warned, especially if it involves new technology, new ways of working, thinking, acting, fast moving environments or tightly regulated sectors – they are unlikely to be as specialist as they might proclaim. Exercise due diligence before committing. Here is a related post I wrote a few months ago.