This restaurant has been here since my grandparents were alive. But it's changed a lot since then.
I've worked out regularly since I studied at college.
What does it mean to say "since my grandparents were alive" or "since I studied at college"?
Some people told me that they meant "since my grandparents died" and "since I left college". But other people seemed to imply that they meant "since a point during the period when my grandparents were alive" and "since a point during the period when I studied at college".
I've been confused for a while. Could you please tell me which explanation is correct?