Time to recovery

When the market starts to fall you hear people pointing out that historically, stocks always go up.
In 1999, when I was starting to seriously invest, I developed a tick. Every time I heard that, I would think 25 years, which is the time from 1929 to 1954. Of course, I didn't say it out loud, but I guess I am now, with this post.
In the case of 1987, it took about four and a half years.
In the case of 1999, it took about eight years for the DJIA, but 18 years for the NASDAQ.
In the case of 2008, it took about six years.