One the past five years, I've attempted to locate/contact a number of former high school and/or college classmates. Of those I located, the results have been mixed.
The first was a guy I roomed with one quarter in college. He was very happy I had located him, and told me he had tried to find me but had the spelling of my last name wrong. We met for lunch and had a great time. We are still in contact.
A couple years later, I finally located another college classmate. He has a very common last name, and I only found him by chance. I called him and very quickly regretted doing so. The happy-go-lucky nuclear engineering student I knew 40+ years ago was miserable and bitter; he whined about his ailments, his crazy wife, his ne'er-do-well son, his job, etc. Even though he lives less than an hour away, I decided not to see if he wanted to get together. I avoid negative people.
The most disappointing search ended when I found my former classmate's obituary. He had died less than a year earlier in Texas. I thought about contacting his widow and/or kids, but ultimately decided not to do so.
There are two I'd still like to find, but no luck to this point. Unfortunately both of them have very common last names.