Acumen celebrates its tenth anniversary this week.

Lesson 1: In fact, you can make a difference, you can start something from scratch, you can build something without authority or permission. Passionate people on a mission can make change happen.

Lesson 2: In fact, philanthropy works. Building systems and enhancing entrepreneurial outcomes generates results far bigger than the resources invested.

Lesson 3: You better be prepared to stick it out, to exert yourself, to last longer than you ever expected and to care so much it hurts.

Some highlights:

• More than 3 million people have access to safe, affordable, and efficient energy
• 7,000 people have jobs and hundreds of millions of insecticide treated bednets have been produced by A to Z
• More than 330,000 farmers are changing their families’ lives with drip irrigation systems
• Hundreds of thousands have access to quality sanitation in Kenya – and Eco-Tact has become a model for other countries
• More than 150,000 farmers have access to quality, affordable hybrid seeds in Western Kenya
• 1298 is now answering more than 30.000 emergency calls every month in India (and has created more than 1250 jobs)
• Kashf has reached more than 300,000 borrowers with micro-loans and emerged as one of Pakistan’s important civil society institution
• The first commercial mortgages for the poor have been provided in Pakistan and Saiban has developed a working, sustainable model for low-income housing development
• More than 350,000 individuals have access to safe drinking water (and this doesn’t include the copycat companies that have emerged as a result of WHI’s innovation in the Indian marketplace)
• Aravind provides quality eyecare through telemedicine to millions across India and has served as a global model
• Sekem is the largest exporter of organic goods from the Middle East to Europe (working with 4,000 farmers on reclaimed desert land)

That a small band of talented, driven people could make this happen isn't surprising to me. What surprises me is that we still wonder whether change like this is possible.