Lots. I just left the reserves after having been in since early 2004. I served both part and full time, domestically and overseas. I got out as a Sergeant, with all my time being spent in the infantry.
I can do some cool army stuff, and that's fine... I've ridden in helicopters, blown up doors with explosives, thrown grenades, shot lots of different weapons... I've had a sprinkling of the 'exciting' stuff. It's fun, but nobody in real life cares about it.
In between that infrequent exciting stuff I've done far, far more. I've taught 17 and 18 year olds how to do things they never thought they would do - safely, under considerable pressure, and while physically miserable. I've taught young mena nd women not much older how to lead and command a team of eight or ten other soldiers, to look after their welfare and professional development. I've learned the limits of my own physical and mental endurance, and then I've learned that much of that was self-imposed and that I could go further. I can stand in from of 10 or 30 or 100 people, project my voice, and convey knowledge that I have and that they need. I can comfortably and confidently grip onto any assorted group of people, and coordinate the accomplishment of a task. I can be given very imprecise directions at work, and know how to clarify objectives and intent, and using said imprecise direction, get something done to achieve exactly the result someone else needs, even if they weren't sure how to put it into words. I can tear down a bad or unsafe idea without undue hurting of feelings, and I can help someone see a more effective way of doing something.
I can recognize that someone has a less than ideal way of getting something done, and I know it - but that that's where they're at in their professional development, and maybe for now I should let them run with it to build their confidence, and then put the polish on later. I can monitor the performance of subordinates, document it, and praise or counsel them accordingly. I can take any knowledge or skill that I have, and put it into a pre-structured format that exists in my head for delivering a lesson. I can look up, interpret, and apply regulations or policies. I got some of my education paid for, and will get more now that I'm out. In my career as a police officer, I've found myself in high risk situations where more experienced members didn't have the tools to call the play, and I've gripped on to ten other officers and started making things happen because leading a small team with a mission to accomplish was exactly in my comfort zone. I got into instructing mental health resilience, use of force, and firearms at an early stage in my career because of my prior teaching experience.
I've been to Alberta, New Brunswick, New York, Kentucky, Texas, New Mexico, Dubai, New Zealand, and Afghanistan. I've staunched a bleeding wound. I've told a colleague his friend was dead. I've seen some of the most abject poverty in the world. I've feared for my life, but knew that everyone around me would do basically anything for each other even if some of us couldn't stand each other personally. I've marched on Parliament Hill. I've mentored kids. I've talked some soldiers and veterans through and out of suicidal intentions. I've failed others. I've lost a friend to his demons, and then tried to help others in the wake of that.
The absolute best and worst times of my life have come from my reserve service. I would do it all again in a heartbeat.