Oh. Boo hiss! I didn't start collecting SSDI until I was 38. I had been collecting private disability (short/long-term) through my job, but that only started when I was 34 and there was a very short period (? months) when I managed to get off of the private disability, working full-time again.

As a side note about short and long-term private disability through an employer:

I know various employers offer different benefits, but my employer offered generous short and long-term disability options. There was one level which was either no cost or low cost. I forget. Then there was a higher "premium" level (though it was likely called something else) that was available for an extra amount of paycheck deduction. In the case of my company, I think most people just went with the regular level. That's what I had, initially. Then when I did finally manage to briefly get back to full-time work, I signed up for the higher level. Then, when I got really sick again and went back on long-term private disability, my disability checks were a notably higher percentage of my usual annual salary. Actually, almost the same. That was mighty helpful. However, when I finally applied for SSDI and was approved, SS paid "back pay" to me for months that I had collected private long-term disability. Yea, I got a big SSDI back pay payment, but I ended up having to repay the private disability insurance company for those months. That sucked because my private disability monthly allowances were notably higher than my SSDI monthly allowances.

Though I will never try to go back to my old job, if I did, the pay even for part-time work would exceed the maximum allowed by SS, at least from what I've heard. Isn't there some cap on how much you can make through the Ticket to Work Program, or similar? If/when I return to any work part-time, I will have to get a lower paying job than I had before SSDI. I would NEVER work my old job, even part-time, for significantly less income (calculated hourly). This whole issue would seem like a major deterrent to getting back to work, for some people. I don't see that as just a matter of preference, but a psychological resistance.