The dynamic scrum-half was dropped by England head coach Stuart Lancaster for the RBS 6 Nations Championship after a series of headline-grabbing, alcohol-related off-field incidents. Lancaster warned him he would have to reform to stand any chance of a recall and adding to his 32 caps.
Care said: "Missing the Six Nations was a hard blow to take but, looking back, it made me refocus my life and my career a bit. It was probably a good thing to realise what I was missing. It seems like a long time ago now - I was obviously going through a tough time and I didn't realise at the time how bad it was."
Lancaster's message had appeared to hit home as Care finished the season strongly with Aviva Premiership winners Harlequins and earned a place in the squad for England's summer tour of South Africa.
Yet even then Lancaster made him wait, overlooking him for the first two Tests in Durban and Johannesburg. That wait might even have been prolonged had Ben Youngs not suffered injury, but he now has the chance to re-establish himself after being named in the side for Saturday's third Test in Port Elizabeth.
Care added: "I will look back and in a way be glad of what happened. It refocused me and made me realise what it is to be a professional rugby player and what an honour it is to represent your country.
"I definitely took that for granted and that is certainly something I will never do again. It has given me the motivation to play well and prove a lot of people wrong and prove a lot of people, who stood by me, right."
Care appeared to be edging closer to an international recall with an influential try-scoring display in last week's midweek tour win over the Southern Barbarians in Kimberley.
It did not happen in Johannesburg as Youngs retained his place with Lee Dickson on the bench. Youngs scored two tries at Coca-Cola Park but Lancaster rethought the situation when the Leicester man was forced home with a shoulder injury. Care will start at the Nelson Mandela Bay Stadium with Dickson on the bench.
Care said: "I was gutted for Youngsy. We get on well. He played well in the last Test, scoring two tries, but injuries are part and parcel of the game, especially against a team like South Africa. It is unfortunate for him but it is a chance for me to get back in there and show what I can do."