One of my greatest mentors was Michael Shef, an English medical doctor with a PhD in biochemistry.

He was my supervisor for a work-study program at the research laboratory of the Benjamin Franklin Clinic.

Dr. Shef’s specialty was the field of phenylketonuria, commonly shortened to PKU.

PKU is a rare, inherited disorder where amino acids called phenylalanine start to accumulate in the body.

This can cause a variety of symptoms.

Some are mild, such as eczema and a musty smell to the urine, skin, or breath.

Some are more serious, including tremors, epilepsy, spasming limbs, tantrums, self-harming, and other troubling behaviors.

PKU is caused by birth defects in the basal ganglia of the brain.

The disease had nothing to do with podiatry. Still, from the start of that work, I was hooked.

My job at the clinic was to take the brains of test rats and separate them into various amino acids using a process called electrophoresis.

We were looking to see if we could spot molecular differences based on the rats’ diets.

We never reached the conclusions we hoped to achieve.

But that work at Benjamin Franklin set me up for a lifetime’s worth of curiosity.

One day, Dr. Shef stopped by my workstation.

For a while, he watched as I painstakingly separated molecules using electrophoresis. Then painstakingly recorded my findings in a ledger.

Finally, he nodded. “Cool,” he said. “That’s very good work.”

That was it, just one simple word.

Still it was one of the highest compliments anyone’s ever paid me, before or since.