What is the definition of mature love?

My boyfriend used to be a heavy drinker before we entered a relationship. However, once we started dating, I kindly asked him to give up alcohol. Without any hesitation, he agreed. It's been eight years now, and he hasn't even touched a drop since.

A few months ago, we were sitting together, casually chatting about various topics. During our conversation, I asked him:

Me: Why did you stop drinking?

Him: I did it for you.

Me: What about temptations? Don't you feel tempted when you're with your friends?

Him: I don't have any temptations.

Me: Why not? What if I were to buy you something you couldn't resist? (I was playfully teasing him)

Him: No, I don't want to drink.

Me: Why? Why not?

After persistently questioning and urging him...

He gently pushed my hair back and said:

My father's life was consumed by his uncontrollable drinking habit, which ultimately led to his death. My mother had to shoulder all the responsibilities. I know firsthand how challenging it is for a single mother to survive in this society. I also know that you are so innocent that you can't even go anywhere without my protection. I don't want you to face the same struggles my mother did. That's why, when you entered my life, I made the decision to distance myself from alcohol.

As tears streamed down my face, my cheeks turned rosy from crying so much.

I said: I love you.

Wiping away my tears, he replied: I love you too, my dear.

I am the more boisterous one in our relationship, while he tends to be more reserved. He doesn't often express his emotions.

However, on that day, his words made me realize that true love isn't about material gifts or indulgences, but rather the sacrifices we make to ensure we can be with our loved ones for as long as possible. True love is loving someone selflessly and unconditionally.

EDIT: Thank you to everyone for the love and upvotes :)

To those who suggested he might be lying: Perhaps he was, but I choose to trust him because love is built on trust.

And to those who claim I will eventually leave him one day: We recently got engaged, and our wedding is set for June (yayyy! :P).

Wishing love and peace to all. :)