United Kingdom, Nov. 26 -- Elizabeth Olsen thinks about mortality "all the time".

The 36-year-old actress plays a 90-year-old woman inside her own 30-something-year-old body in Eternity, the new fantasy romcom, and Elizabeth has explained how her latest movie has influenced her own approach to ageing.

She told The Hollywood Reporter: "I think about mortality all the time. But Eternity has actually made me think even more about how ageing is such a privilege and how badly I would love to grow old.

"It's something I'd already been thinking about, because I wasn't lucky enough to meet more than one grandparent.

"You just don't know if you are going to have that opportunity to grow old. You don't know when your time is going to come. But ...