I'm not really one to get diseases. Beyond the occasional cold (like every 3 months or so), I almost never get sick. I have a really good immune system.
That said, nobody has gone their whole life without some form of illness, so obviously I have had something. I don't remember it at all but apparently I got chicken pox when I was really little. That's something all my sisters went through, so my parents were expecting it and knew what to do.
I came down with appendicidis when I was 10. The stomach pains were unbearable. We were told I was going to need surgery, but we didn't have a qualified surgeon in my town, so I got rushed to the nearest city that did (which is about an hour drive). Ended up spending the night in the hospital. Thankfully, my appendix decided to start working again so surgery was not needed. But that truly was an agonizing night.
Most recently, I got strep throat last summer. I remember the throat pains really well, it's not something I ever want to go through again. I made sure to swallow as little as possible, and to do that, I stopped eating as much as I normally would, and I tried to avoid hard food at all costs. It took about 2 weeks to go away, and it was not a fun 2 weeks, especially since I still had to go to work.
I'm grateful to have never come down with anything super serious. I had a close call with measles one time, but I got vaccinated just in time to avoid it (I was directly exposed to the disease prior to vaccination so it's a wonder how I didn't get it).