Chris Brown won Rihanna back recently after beating her in 2009 by showing her how remorseful and sorry he is for the incident.The R&B star - who is still on probation for beating his girlfriend in 2009 - is "extremely grateful" that the 25-year-old 'Stay' singer took him back recently and says that the incident made him realise he could "lose it all".The 23-year-old 'Fine China' singer told Ryan Seacrest on his KIIS-FM show on Tuesday (26.03.13): "It's all about my responsibility. I just tried my best to be the best man I could be over the years and just show her how remorseful and sorry I was for the incident and that time was probably the worst part of my life and being that she has and she's a wonderful person I'm eternally grateful and thankful."Chris admits that while he has won back the affections of Rihanna, many of their fans are still skeptical that he has really changed but he insists he has grown up.He said: "People are entitled to their opinions. I can't go around blaming. It's all about my responsibility and me growing up as a man. I think now that I'm becoming older, and trying to mature in this life under the public eye at all times, I have to focus on doing the right thing and being more of a humble individual."And I'm not just saying fame or stardom because that's not what it's about. I'm talking about dignity [and] integrity. You know, you lose yourself in a way. So that process of me having to deal with any trials and tribulations I went through at that time, it was a learning step for me. Everything was learning, and I learned from certain mistakes, and I'm getting better as the days come."But despite being more in love than ever, Chris revealed that the couple behave like children and enjoy the simple things in life.He said: "It's still like we're kids. I try not to be too grown and be like, 'Lets have candlelight dinner every night.' I try to make sure everything is fun. It has to be fun and it has to be genuine."