Gareth Barry has endured one of the most disappointing weeks of his helter-skelter rise to the top of his profession.

But the England defender is determined to treat the experience as a lesson learned.

Barry, who turned 20 last week, has tasted success all the way since breaking into the Aston Villa team two-and-a-half years ago.

He has been a first-team regular under John Gregory and an established member of the England senior side this season, starting the internationals against France, Finland and Italy.

But in the past few days he has been left out of Sven-Goran Eriksson's first squad and conceded the decisive penalty in Villa's defeat at Derby on Saturday.

On Tuesday he was part of the England Under-21s side mauled 4-0 by Spain at St Andrew's.

Barry believes the under-21s can learn much from the performance of Spain and he feels the same is true for him on a personal level when it comes to assessing the events of the past week.

The former Brighton trainee said: "It's not been one of my best weeks! Being left out of the England squad was not a good start. I found out from TV. No one made contact to let me know.

"Then I gave away the penalty on Saturday at Derby, and it got worse on Tuesday against a very good Spanish side who deserved their victory. It's not been the greatest few days for me.

"I watched the England game on TV at home. It was strange. I've been involved for a year in the squad. It's was a bit hard, but I hope I won't have to get used to doing that."

Barry has lost no belief in his own ability, though.

The defender is touted at £20m on the transfer market and been linked with Manchester United, Arsenal and Inter Milan.

The former William Parker, Hastings, schoolboy expects to sign a five-year deal with Villa at an estimated £16,000 a week by the summer. The trappings of success are embodied in the Porsche he has parked at Villa's Bodymoor Heath training ground.

Yet his arrival at this point has involved personal sacrifices and lessons learned from mistakes off and on the field.

The closest thing to his heart is his family. One of six children, an uncle to seven, moving away from Sussex was heartbreaking but he feels he had to make the break.

He said: "It was very hard coming straight here after leaving school. One of the negatives for me was being away from my family.

"There were offers from London clubs but if I'd accepted I would probably have wanted to go home all the time. That would have been the easy way out.

"But coming to Villa made me grow up. That's what comes of being away. You've got to look after yourself. You have to mature.

"My life has changed so much in four years. I've lost a lot of friends and I only get down to St Leonards four or five times a year, although going home now is something I really look forward to and, with what I earn now, I can look after my big family. The money is one of the rewards for doing well."

He described learning to deal with the size of his income as "an awkward but nice adjustment".

Getting to grips with fame has been more difficult.

Barry's manager John Gregory, a former Albion player, said: "Gareth lost his way a little bit on a couple of occasions in the early days. Now he is focused on his job and can achieve anything he wants to."

Barry knows rich young footballing superstars in public are prime targets for the resentful, while the paparazzi wait in the wings. He said: "You just know there are things out there that can cost you your job, like going out all the time and getting drunk. You know you are going to make headlines if you get into trouble.

You're a well known person so people are going to give you looks. You just try to stay away from it. I keep myself to myself. If any trouble comes along it's best to ignore it.

"You learn from your own and others mistakes. There are a lot of experienced players to advise me at Villa."

Gregory and club captain Gareth Southgate, from Crawley, have helped. Barry said: "The manager played me at 17 and has shown so much faith in me. That has given me confidence on and off the pitch. Gareth is a massive influence."

Villa reserve midfielder Michael Standing, 19, from Hove, has also played his part. He is Barry's partner at snooker, computer games and clothes-shopping, housemate and friend. They both came from Sussex to the club at the same time.

Barry said: "We've been mates for a long time. As a footballer you get a lot of spare time and it's good to have him around."

Albion, of course, played their part. He said: "I had some good times there. Even if they were in the lower divisions it was still a brilliant thing for me as a schoolboy to be associated with a professional club. I was glad they got a bit of money for me (which should amount to around £1m). That's helped them and they're turning the corner now."

But Barry's maturity has largely come from within. He is no longer the reticent individual who first arrived at Villa Park. He has perspective and opinions while retaining his natural reserve, a disarming blush and occasional wide smile.

He said: "I've got a nice car and a nice house, but I'm looking to the future. You never know what's around the corner. If a serious injury comes along you are out of the game and suddenly the money's not coming.

"I've had a lot of positives so far in my career. But I'm always aware there are going to be a few negatives and I'll always try to make sure that when one comes along, like being left out of the team, I'll be ready for it and not sulk, even though it won't be nice."

He is happy with Villa despite speculation suggesting interest from more glamorous clubs.

Barry said: "I will be signing a new contract.

"It's nice hearing compliments linking you with other clubs. I'm ambitious and I haven't won anything yet with Villa and my target is to win things and sometime you just might have to make a change."