The 48-point deficit at full-time was Scotland's biggest ever margin of defeat in the Championship.
But Fife saw enough in the previous two games against France and Italy to suggest the Wales game was just a one-off.
"We have gone backwards with this result but I don't think we will worry about that too much because the positive steps we've taken in the two games before this were massive," said Fife.
"It's always difficult when you go down to 14 men that early, but even more so against a team like Wales.
"We spoke at half-time about trying to shut-up shop by keeping hold of the ball. At points we did that. We had a 20-minute spell when we kept the ball in their half and took it to them.
"But it is tiring. Going through phase after phase, you know at some point you are going to give away a penalty and then they will be back in our half."