I don&#x27;t know your personal circumstances, but I do know that there are roles for mathematicians to play in many areas outside of academia, and that your age wouldn&#x27;t preclude these possibilities. If you haven&#x27;t already, there would be no shame in beginning a PhD at your age (even some successful academics have done so).<p>We are all lucky and unlucky relative to someone else. I think time used on regret or &quot;longing for what could have been&quot; is simply time misspent, much like you might regard your childhood. Best of luck overcoming this natural tendency.