It's not telling them what they are but discovering things about them and accepting every millimeter of it.
It's making them live the life they wanted and support them in any way possible.
It is indeed investing every single thing you have. Time, trust, efforts, money, happiness, your body and soul, patience and a lot of many things.
It is getting into an argument with them then make up after you both realize you were both wrong even though you know you were right.
It is apologizing for a mistake that you never did but you'll say sorry by the way.
It is being comfortable with them even in the most awkward moments.
It is when the time seems to slow down and picks up its pace whenever you are together.
It was never forcing them to do or tell you things but wait patiently even if you think it takes forever.
It is appreciating every perfect imperfections they have.
It is living the future and not the things that must be left behind.
It is putting on all your trust in their hand and know that they will never drop it.
Sure they might hold it loosely or tightly sometimes that it will hurt, but you knew they will not let it go and you can assure them that you'll do the same.
And it is being with each other laughing your ***** off, falling your faces, getting annoyed at something together and so on.
It is making your hearts have a synchronized rhythm.
And here I am telling you what is love when I'm another oblivious kid was never in a relationship. Pardon me. Lol