I left Boeing at the end of 1999, and at that point, I think their stock was around $45/share. That would have been the last time I invested into the 401k. I remember the sum total of my investments plus the company match was roughly $5810 at the time, and I think when I left, my 401k was actually at a slight loss.
But, thankfully, I just left that 401k alone. Just a week or so ago, it was up to a bit over $61,000, although it had taken a trim by Friday. And I know today's going to hurt a little. As time went by, I did move a bit of the funds into a bond fund, and an SP500 fund, but I think the account is still something like 81% in the stock fund.