The key to successfully multitasking? "Get really good at saying no."
That's the message from Jared Leto, Academy Award-winning actor, rock star and successful tech investor.
"You have to be really good with your time. You have to be incredibly focused on what's important, what the priorities are," Leto told CNBC's "Squawk Box" in an interview Tuesday.
"In a band ... it's very similar to a start-up. You're a few people in a garage," he said, recalling the early days of "Thirty Seconds to Mars."
Leto learned to "play a lot of roles" with his band, not only as singer-songwriter but also as marketer and social media advocate.
"It put me on the path early on to be independent and entrepreneurial. And it lead me to the tech world," he said, adding tech investing was something he started to do quietly 10 years ago.