The Chiefs flanker is one of four uncapped players in the 39-strong group for the first two matches against Argentina and South Africa.
"I didn't really see this coming at all," Jacobson said.
"I thought I'd missed out on the selection because someone told me that you're meant to get a call before.
"I was like 'oh well, sweet as I'm a bit gutted but I'm still young so I've still got plenty of time' sort of thing, so getting named was pretty cool."
Jacobson, 22, did not get an indication from the All Blacks selectors, having not had any contact with the coaching staff.
"I hadn't talked to the coaches until this morning when they congratulated me...when I rocked into the hotel."
Jacobson has found it "a little bit daunting" joining the All Blacks in camp in Auckland.
"There's a lot of big dogs around and I'm just here like geez 'I'm Luke' sort of thing," he said.
"It's exciting at the same time. Little bit nervous, a little bit on edge but I imagine other guys are as well, the new boys.
"So I'll just get over that and introduce myself to everybody and get to know everybody and hopefully feel a little bit more at ease."
Luke Jacobson has benefited from incumbent All Blacks blindside flanker Liam Squire making himself unavailable for selection, and Squire is a player he's hoping to emulate.
"Liam's definitely a player I look up to.
"I think he's the best six in the country. When he's on the field you know he's there.
"He's a huge presence, throws his weight around, is hugely physical and you know he's got some pretty barnstorming runs in that as well."
Jacobson missed the end of the Chiefs' Super Rugby campaign because of concussion, but has been cleared to return to play.
"I've actually played club [rugby] for the last two weekends for Hautapu.
"I played 40 [mins] the weekend that the Chiefs played the Jaguares and then I played 60 last week so all good."