I started programming professionally over 10 years ago. As a student working full-time I had a mentor who treated me as an equal. He taught me a tremendous amount about networking, C, C++ and was a very good friend. One of the most important things he taught me was how to tell my customer "no". "You can't just say 'No.' You have to say 'Yes, I can implement that given adequate schedule and budget.'". I use those words often. I even taught him some new techniques that I was learning in school.
Over the years we each moved on in our careers and lost touch. And today I'm extremely sorry about that. The world lost a great mentor today. I hope I can pass along to others the wisdom that he passed to me. Luke, you will be missed.