Personal Opinion
SO throughout the Entire One Piece series ( 1999 - present ) luffy has aged from 17-19. Luffy has not only developed strength but developed in his friendship skills as well. Luffy has also learnt that the world isn't as free and nice as you see it, there will always be some form of injustice. Luffy also learns that not everything will go according to plan, and that he also went through different emotions, grief, happiness, anger, guilt and other normal emotions.
"If you don’t risk your life, you can’t create a future. Right?" ~ Monkey D. Luffy
If you don't risk then you really can't get anywhere in life, You need to try and if you fail then you try again, sometimes risking can lead to better things.
"I was asleep for three days!? I’ve missed 15 meals." ~ Monkey D. Luffy
Food is life, no one messes with food, we need food to survive and food is just... food
If I get reincarnated…. I wanna become a clam" ~ Monkey D. Luffy
I just wanted to add that because I can relate to what Luffy said, sometimes I just think life is so boring that I want to become something entirely different.
"I know that I need others to help me if I want to keep on living!"~ Monkey D .Luffy
Don't let our ego and pride get the best of us because sometime in life, we need to have people to back us up and we need people to help when life gets hard or when we need help. Not everything is about being independent, we need to rely on others in order to achieve our goals
Overall, Luffy has reminded that Friends and Family are one of the first priorities and that we should always protect our friends and family