While some people attribute their luck in the stock market to skill, it is still possible for someone to have actual skill in making money in the stock market. Some high-profile billionaires and numerous quants have demonstrated this. The fact that you made money doesn't mean your income is solely, or even primarily, attributable to luck.
Likewise, it's possible the grandparent has been lucky that the projects they've forecasted aligned well with their areas of knowledge and hit no problematic snags. It's also possible, however, that one can develop the ability to make mostly-correct predictions about project timelines. Being a rarity doesn't mean it's flat-out impossible, or even unbelievably improbable.
Likewise, it's possible the grandparent has been lucky that the projects they've forecasted aligned well with their areas of knowledge and hit no problematic snags. It's also possible, however, that one can develop the ability to make mostly-correct predictions about project timelines. Being a rarity doesn't mean it's flat-out impossible, or even unbelievably improbable.