It hit Buffett that many of us only have about 40 years to achieve our goals.

In his campaign to eradicate food insecurity, he spends part of each year teaching farming methods and trying to improve people’s lives in more than 120 countries.

He soon learned his efforts and those of other nongovernmental organizations (known as NGOs, usually charitable groups) often aren’t as successful as first visualized, usually due to a lack of knowledge of the area.

For example, when a program used American grain surpluses to fight world hunger while helping American farmers find a market for their crops, Mozambique farmers who also sold corn saw their market price drop and provide less income for their families.

Many nonprofits don’t factor in how locals would handle a situation.

Local corruption often diverts aid; in South Sudan, for example, armed groups of militants blockade a village and take about 30 percent of food sent by an NGO, enough to supply themselves while keeping villagers hungry but not so much the NGO will refuse to send more food.