Uma Thurman misses being a "passenger" on close friend's Natasha Richardson's driven life.

“She (Natasha) would have a plan on arrival anywhere and would be carving the best out of life and every situation and every person," Thurman tells the July issue of Harper's Bazaar U.K., on sale today. "She wasn’t as much a passenger as I am, which made us great companions in life … because every driver needs a passenger … and every passenger needs a driver. So it’s a big loss in my life.”

Richardson's death from a freak skiing accident earlier this year has inspired Thurman to make sure she lives her life to its fullest. The 39-year-old actress, who was married to and shares two children with actor Ethan Hawke, is currently readying for a London wedding to British tycoon/philanthropist Arki Busson.

PHOTOS: Uma Thurman's sexy photo shoot in Harper's Bazaar.

“Isn’t life amazing? Isn’t life full of surprises? When it comes to things like marriage, you just never know," Thurman says. "I find that growing up has been all about realizing that life gets more serious, and that it’s also really important to increase your sense of humor.”

Apparently, for Thurman, it's also really important to increase the number of houses you own in posh vacation destinations.

“I would buy a country house in virtually every country in the world if I could," she said (and with Busson's billions, she probably could!). "I also want a country house in Italy, France, Switzerland; I have aspirations in Mexico …. virtually all coastal regions. I just have this constant curiosity to open a clam in every country and eat the squirming things from every shore.”