Recently, I've been to learn Italian.
Putting its grammar aside, I found it difficult for me to pronounce 'r' in Italian. No matter how many times I tried, I was unable to properly pronounce it. At first, I was really upset and disappointed. But lately, I had no choice but to accept this fact and pronounce 'l' to replace 'r'.
Though how to pronunce 'r' in Italian is still a mystery to me, it's said that everyone is able to pronounce it if you get the technique. Well, I hope I can suddenly realize this technique one day.