Smashboards

That's pretty difficult to answer, honestly. Ego isn't something you can get rid of entirely, you just have to not let it dictate your actions and minimize its influence as much as possible. The best way I can explain it, is to remember that any losses or being held back is temporary. Skill building doesn't really work in a linear fashion, but it also has diminishing returns. Meaning, whether you or your friend is the one that's ahead, is completely arbitrary as you guys will end up at the same destination anyways.

You were only winning because you exploited your friend's weaknesses and beat him with experience. As he continues to play and practice, those weaknesses diminish and it becomes harder and harder to find easy ways to exploit them. Eventually, no matter how far ahead you are, he will eventually catch up and be at your level. Because there becomes a point in time where your weaknesses become scarce and it becomes much harder to significantly improve, because there isn't too much left to work on that will substantially improve your play.

You are used to beating him all the time and you ended up seeing yourself as "being above" your friend. And now that he's catching up and challenging your position, you are starting to become angry and feel threatened. That's completely normal, and happens to a lot of older people that see those they used to consider inferior to them catch up and challenge their position. It's a natural part of life for the young to surpass the old, but it doesn't make it any easier for the old to feel like they're becoming irrelevant.

You've felt you were stagnating and decided to try new things. And in the process of learning those new things, your friend is now beating you with the muscle memory and strategies he's honed over the years, while you're getting used to a new way of playing. And now he's feeling empowered that he's all of a sudden beating you and you are feeling like you're getting weaker because of it.

That's not really true though. You are practicing and trying to find new ways to refine your current style. And you are going to be temporarily weaker because you haven't gotten used to it and haven't built the muscle memory yet. And you can prove that by going back to your old tricks, but you will still have the same stagnation if you don't seek to change and modify your current style. You'll be able to beat your friend, but still be frustrated at not making any headway.

So you have to try and remember that any losses that you will incur are temporary. Once you've managed to incorporate the new stuff into your playstyle, you will be back to beating your friend and even stronger than before. And then your friend will have to deal with the fact that his stuff is no longer working again and be forced to modify it or face being a perpetual loser.

So try to laugh it off for now and then when you do get stuff mastered is when you can show him up and lord your victories over him once more. Don't be too focused on the present and instead focus on bettering your future. You lost so many times that you probably can't count them all when you first started learning the game. I know I did. And yet, none of those matter to me anymore, because I'm not the player I was two years ago. In fact, I'm completely unrecognizable to the guy that always spammed Nayru's Love and dash attack on For Glory. And still won half my matches. -_-

So the trick to learning how to improve long term, is to always be looking at what you want to be in the future and not what you are right now. Improvement will slow and stagnate at certain points and sometimes it's difficult to see what you need to do next. And sometimes you need to suffer temporarily in order to keep moving forward. So don't get too caught up in short term results or proving to your friend that you are still top dog. If you guys have been playing each other this long, there are going to be plenty of chances to even the score in the future.