Because I love startups I signed on for a *substantially* lower rate than I usually contract for. I also donated countless hours because I wanted to see the company succeed. I was "on call" all hours of the day, which the employer took advantage of - for crises that generally followed the pattern of "This button's color is wrong. Do you listen to anything I say?"
In the 9 months I worked there, I got one paycheck on time. The other 8 paychecks were invariably 3-7 days late.
The employer was often overtly condescending, passive-aggressive, and emotionally volatile.
When I decided I'd had enough, I submitted a polite and professional two week's notice. He argued and begged me to stay on until he could find a replacement. Several weeks later he still hadn't interviewed anyone, and was still calling me at all hours for support.
Eventually he hired someone and I provided training. He never sent my last paycheck, and I didn't receive my tax information until over a month past the federal deadline.