Rob J. wrote me an email a couple years back, out of the blue. We’d lost touch since our days in Boston, as close friends back in our 20’s.

His email told me how he appreciated our friendship from those distant times past. My first response was sorta cynical. I thought maybe he was in some type of self-help program.

But his words were kind and sincere. And that email stuck with me.

Inspired by Rob, earlier this year I started sending thank-you emails to friends new and old. In some cases, I’d just thank them for our friendship. In others, I pointed out something they did or said that helped me. My hope was that maybe I could help them appreciate the positive effect they had on my life.

I sent these emails because it made me feel good. And I hoped they would make others feel good, just the way Rob’s email stuck with me.

Last week, news of my departure from McAfee was announced. I got many kinds notes and calls. And in some cases people cited examples where I had a positive impact on their work or professional lives.

Some of these examples surprised me. Seemingly small or trivial things I did or said had a positive impact on others. I guess I shouldn’t have been surprised given my experience with thank-you emails.

What I also took away from these notes is that as a leader, one’s words and actions can have a much larger effect on people than one might realize. This can produce both positive and negative effects. It’s an awesome responsibility one bears as a leader.