Scott, who moved from Edinburgh to Gloucester last season, played no part in Scotland's three-match autumn Test series and only featured briefly in one game in the  Six Nations - a try-scoring cameo against Italy.
Gregor Townsend has selected Scott from the beginning against the Italians in Singapore on Saturday. It will be his first start for his country in a year.
"It's been a target of mine to get back in the team," says Scott. "I'm delighted to get a chance to impress the new coach."
"Not being involved at all in the autumn was really horrible and hard to take," Scott added. "I took on board the feedback from [former coach] Vern Cotter and thought I really needed to have a positive attitude.
"Everybody around me - family and friends - were saying, 'You're not in the squad, you must be raging' but I had to use the disappointment to try to get better. I used it to drive me on.
"I had a chat with the defence coach at Gloucester and he said, 'Right, defence is one of the things they want you to improve, so let's improve'.
"You're maybe grumpy for a day or two but I had a chance to put the past to bed. I think I've improved on the field and off the field as well. I've grown as a person."
Scott says that, effectively, there has been an internal ban among the players about complaining about the soaring heat and humidity in Singapore ahead of the Italy game.
"We got in the huddle at training and [Scotland captain] John Barclay said, 'Boys, I don't want anybody talking about the heat anymore, nobody can moan about it, we all know it's hot but it's going to be hot for Italy as well'.
"We need to go in with a positive attitude. If we go in saying, 'It's going to be hard' we might lose 10 percent energy-wise and we might start thinking we're more tired than we actually are.
"We said we've got to bring each other on during the game, encourage each other, make sure we're always chatting.
"It's probably going to be one of the hardest games we're going to have to play in terms of the conditions, but we've got our heads around that."
Scotland centre Matt Scott says a positive mental attitude has revived his international rugby career.