[xwdv]

No. You can start a startup at any time.

What people mean when they regret not doing a startup they mean they typically regret not trying to start one when young, having it become a booming success and then reap the rewards for a larger portion of their lives.

There are better regrets to avoid in life; the regret of a lost love, the regret of not reconciling with your parents, the regret of not having a child, or the regret of not tending to ones health.