He knows what he can get done, and what he can't.
I concur @PrincessNutNuts
How much of that is due to how badly he got it wrong in the first wave.... I don't think I'll ever forgive or respect him for THOSE mistakes.
There's an element of truth in the claim that the UK couldn't have done what OZ/NZ did (caveat before vaccines). For starters how would we have handled lorries coming from the continent? Locked the drivers in their cabs while they were in the UK?!??
However, we needn't have been so hell bent on spreading the virus as quickly as possible - all due to belief that achieving herd immunity as quickly as possible without overwhelming the NHS was the best plan - i.e. ramp numbers up quickly, THEN try to suppress and hold at that level. Scientifically it was complete and utter madness!!
In a different universe, the UK could easily have done what Germany did, with less effort! As an island we have a natural advantage. We could have maintained infections at a lower level, kept schools open, protected care homes and generally lost a LOT fewer lives.
Moving forward, the vaccine enables us to achieve what NZ/OZ have done far more easily. Although no vaccine is perfect at preventing transmission, they are sufficiently effective to make eradication of the virus a possibility. Much depends on future mutations and whether or not vaccines CAN be tweaked to combat them, but I'm optimistic we can now beat covid.