Running???

I started running about this time last year. Before then the only running that I had ever done was back in school (and then it was just for the physical fitness tests. lol). I've never been an athlete. I have never had the desire to run..........EVER. Then I decided that after 6 months of consistently exercising that I needed more motivation to keep going, so I signed up for a triathlon. WTF was I thinking? I'll never know. lol Anyway I had to force myself to start running. When I started running I couldn't run more than a couple minutes before stopping to walk for 5 or more minutes, then I'd try to run again. It was horrible. I thought that I was going to die. My lungs were on burning and my head was on fire. I could easily push myself on my elliptical machine for over an hour without any problems but I couldn't run more than a couple minutes at a time. I just wanted to quit and I guess I'll be honest and tell you that I didn't practice as much as I should have because it was so frustrating. I was slowly able to go longer stretches and somehow survived the triathlon.
Fast forward to today. Yesterday I ran 2 1/2 miles (with a couple short water breaks after I was about half-way done). It's so weird. I still don't like running but for some reason I miss it and crave it when it's been a while since I have done it. What is this all about?