Unless the price is truly egregious, never substitute a business you know intimately for one you don’t because of valuation alone.
Mistakes are part of investing; they’re unavoidable. The key is learning from them. Reflecting on where you went wrong sharpens judgment, refines decision-making and, ideally, stops you from making the same mistake twice.
My own most glaring error is simple, and one I have made many times: selling compounders too soon based on valuation alone.
A compounder is a business that consistently reinvests its excess cash flow into high-return opportunities, fuelling long-term growth. Selling it prematurely, without assessing how effectively it reinvests, can mean walking away from years, even decades, of compounding returns.
Source: https://www.afr.com/wealth/personal-finance/i-m-a-family-office-cio-this-was-my-biggest-investing-mistake-20250317-p5lk4t