I honestly don't really like lessons in life because it usually means that I have messed up pretty bad, or I'm getting prepared to do something WAY outside of my comfort zone. I've learned a few lessons so far this year, and it's only the last day of January. Anyway, one of the toughest lessons I have ahd to learn is to follow God and not your heart. Lessons are meant to teach us. When we are beeing taught somethingin school, we are required and expected to learn it, and not make the same mistakes over and over again. Same with life lessons. Like for me, I am now expected not to follow myheart, but to follow God. He's teaching me these things, and he wants me to do well, and to do things right. Let God teach you and guide you because you aren't supposed to live life on your own without any help or correction. He created you so that in your life he can be glorified through you. That's why he corrects you and teaches you. He does it for His glory.
(Now I have shared one of the lessons I have learned, and if you want to tell me what you have been learning too, you can leave a comment :D)