One of the most valuable things a leader can leave behind is a lesson"a piece of information or experience that others can use to improve. The longest-serving sergeant major of the Army left this lesson: Take what you have learned and pass it on.Kenneth O. Preston, the 13th SMA, retired in March after serving seven years in the position. During his tenure, he helped shape the way the Army manned, equipped and trained the force, and advised noncommissioned officers to teach others whenever possible.Preston joined the Army straight out of high school, after considering all the services.“I didn’t necessarily have the grades that would get me a scholarship, wasn’t going to get rich throwing a football, so I just looked for an opportunity to get away from the small town that I grew up in, in the mountains of western Maryland,” Preston explained.Though he originally wanted to do something that involved architecture, Preston signed up for the armor career field at the prompting of a recruiter and in March of 1975, was sworn in. He made the rank of sergeant two years later.Preston has been stationed all over the world and has deployed to Kuwait. During his career, he taught armor officer basic courses at Fort Knox, Ky., went on an exchange tour in Britain (where he taught scout and tank weapons systems) and served as the deputy commandant at the NCO Academy in 1992.He also served as a cavalry scout and tank commander during his 35-year career, and as the command sergeant major for the Combined Joint Force Task Force 7 in Baghdad.“Every unit and assignment I’ve ever been assigned to has been a wonderful experience,” he said. “I’ve never had a bad assignment or experience as I look back over my career.”Preston took his position as the SMA, Jan. 15, 2004. “I fell in as a member of a team,” he said, acknowledging that the efforts of the total force serve as the foundation for the Army’s achievements. His first challenge was helping the chief of staff of the Army"then Gen. Peter Schoomaker"man, equip and train large numbers of Soldiers who were forward deployed to Iraq and Afghanistan.“As sergeant major of the Army, your goal is to support the chief of staff of the Army and contribute in making the Army a success,” Preston said. “And my view of the SMA is a force provider.” Preston’s goal in that role was to help the units, leaders and organizations to be successful.“The focus in coming here was manning, training and equipping…making sure our Soldiers had the best equipment, the best training, and had the right skill sets and the right numbers of people in their units or organizations for the missions which they were being asked to do.”The active duty Army was transforming into a modular force in 2004, Preston explained. “We had to do a lot of balancing in the Army. There were a lot of formations that were heavily weighted to the Cold War threat…we had a lot of heavy forces and not enough of the stability kind of forces that we need to be a success.”Since then, the Army has grown by almost 100,000 Soldiers, and Preston said the force is better equipped than it was at the start of his time as the Army’s top enlisted Soldier.“If you look at photos of Soldiers in 2004 and you compare them to photos of Soldiers now, it’s like looking at Soldiers from the Korean War. In comparison…we’ve come such a long way in all the different types of equipment"not only our uniforms, but our gear, our body armor, all the equipment to protect a Soldier out on the battlefield,” Preston said. “The whole transformation of the Army, in my mind, has been the biggest accomplishment that’s really taken place.”Training has also become more relevant over the past seven years, he said. The Army has taken all the lessons learned on the battlefield and incorporated them into training, so the force is better prepared for wartime missions. Preston believes that professional military education is key to supporting an Army at war. “We have taken an Army that was the best Army in the world and taken it to a whole new level.”As a former instructor, Preston emphasized the importance for NCOs and other Soldiers to take every opportunity to teach and become subject matter experts in their fields. He attributed his military success and strength of character to NCOs who imparted their knowledge and mentored him throughout his career.“The most valuable contribution that any senior noncommissioned officer can give back to his or her Soldiers is to be a teacher,” Preston said. He hopes that as the Army increases dwell time between deployments over the next few years, NCOs will take on the roles and responsibilities of teachers and SMEs, positions currently held by contractors due to the short deployment cycle.Though Preston had command experience before becoming the SMA, he soon realized that he didn’t know as much as he thought about his new responsibilities and the Army. He found a plethora of information at his fingertips, however, from historical files to contemporary reports, and he studied them at length. Reviewing this information helped him to understand the Army’s decision-making process across the manning, equipping and training spectrum, which in turn made him a better enlisted leader.Preston said he advised his successor, new Sgt. Maj. of the Army Raymond F. Chandler III, who was the first enlisted commandant of the Sergeants Major Academy, to command and learn the Army from a historical perspective.“Learn where we were in 2004, learn how and why we evolved to where we are today, because (that) will really help in understanding not only where we’ve been and where we are today, but where we want to continue to strive for the future,” Preston said.Upon retirement, Preston said he planned to go back to Maryland, “back to the farm,” to figure out the next chapter in his life.“I like to joke around with the young Soldiers: ‘I don’t know what I’m going to be when I grow up,’” Preston said.