So, you sell shares. You rebalance your portfolio. And, because of this, your initial investment grows by less than the 20 times. Again, I'm definitely not saying rebalancing your portfolio is bad. I'm just saying that risk aversion is a very real factor to consider when contemplating the real upside of any given investment.
Risk aversion affects realizable returns.
But, you probably won't be aware of the psychological limitations in your best preplanning.