Southgate concedes he doesn't unanimous popularity amongst England fans.
Asked if Sunday's game will set his legacy, Southgate said: "It will. But in the eyes of others.
"Where I’m fortunate is that age and experience has made me more comfortable with who I am, what I’m good at, what I need to be better at.
"I completely understand that in the end winning, and what that means, completely changes how you’re going to be viewed by other people.
"But the margins are so fine, and there are bits you can affect, others you are not going to affect.
"Had we gone out in the first knockout round here, I know I’ve managed this period better than I did in Russia (in the 2018 World Cup), but that wouldn’t be how it was viewed and it would sound like nonsense to the man in the street, I completely understand that.
"I want to win so much on Sunday it hurts, don’t get me wrong, but I can handle whatever comes and I know it’s not going to change what the dog thinks when I walk back through the door."
Southgate also said of his critics: “I am fortunate that I am the type of guy who you have to prod a lot to get a bark.
"That’s just how I am. I don’t know why that’s how it is, probably something I get from my Dad. He always managed his emotions really well.
"I have to accept that Didier (Deschamps, France manager) has had lots of criticism, Pep gets lots of criticism, Jurgen got lots of criticism.
"I’ve got my head round what that is now.
"I’ve got perspective, because I’ve seen people who have won things. Most national coaches here will have had criticism over the style of play, over selection or over results. It is what it is. Ours is maybe a bit louder because of expectation, history, everything else. But I understand it and that helps me rationalise it."