Exercise your options - lesson learnt hard way

I left Mixercast some months back and couldn't exercise my stock-options due to various reasons (new place, new job etc), I forgot it totally. Now ninety days are over and I am (or have) screwed up. As far as I know or told, nothing can be done.

I knew, Mixercast would do well and my reason to leave company was something different. I feel, I had worked hard enough to reach a state of burnout.

Anyway, a lesson learnt, always exercise your options, if you believe in the product/startup/company and have worked hard.