You're an older sibling, and you would probably spend more time with him than most people. If you have a strong bond then it makes sense that you would feel that way. He still has quite a long way to go before he turns into a man though, believe me. I have a 4-year gap with my younger brother, and he's in high school now. I still find ways to help him out and make sure to keep talking to him, so he knows that I'm always there to support him no matter what. I sincerely think that the best you can do is help him through the new struggles that he will start going through and make sure you're the caring older sibling that you've always been. It's normal that you want things to remain the same though :( But growing up is a part of life, and when you become an adult too he might be sad that you're not as young as you used to be. Cherish the moments you have now, and don't take the time you have left for granted.
