Why didn't Trunks train with Goku? Or ask about goku's outlook on training?

So Goku's presence is so important that trunks was sent back in time to fix the timeline. So I feel like the mindset or overseeing of trunk's training was needed. So why didn't he? To an extent Vegeta's mindset was imprinted on to trunks as it should've been(trunks not being satisfied with ss2) but Goku clearly had something Vegeta didn't have at the time. What could Goku have imparted onto trunks for him to not need to comeback to the past anymore?