One time I bought a huge watermelon - probably the largest I've ever seen - from a farmer's market in North Carolina. I was living alone at the time so I didn't have anyone else to share it with, but I brought it home and carved it up.
Even though I ate six or seven large slices a day, five days later I still had a substantial amount of watermelon to get through. At this point, the core was starting to become translucent - which is a sure sign that your watermelon is growing old. However, I didn't want to waste any of the fruit, so I doubled my efforts - eating double the amount I had before.
Now, twelve slices of watermelon a day will do all sorts of funny things to your bowels; despite the color change, consistency change, and the constant gurgle of my stomach I pressed on.
Two days later I only had a quarter of the behemoth left. By this time, I had to physically crawl between my bed and the toilet / kitchen. It was agony. Every time I crawled across the linoleum floor, I could see the watermelon, which by this time was starting to get rancid, taunting me on the counter above. I had to slow my pace, eating maybe two or three slices at this point, or else I felt like my stomach would immediately reject it.
It took me four more days to finish that watermelon. I'll never forget how that fruit made me feel.