Love is when all you care about is their happiness, safety, and health. If they are gone for more than 2 minutes you already miss and long for them to be next to you. Their smile makes you melt, their presence makes you grin and feel happy. Like a burning fire in your heart erupts when you fall in love with them and never goes away. Just a simple hug from them makes you feel unreal. A kiss from them makes you feel loved and makes you want to show your love for them. You would die for them, you also sometimes cry for no good reason, other than, you want them by your side. You actually find yourself listening to love songs and think about them day in and day out. You want to hug them and never let go; you want to gaze into their precious eyes like there is no tomorrow. They are beautiful. You've felt attracted to others, but she/he never leaves your thoughts. You can not picture or imagine yourself loving anyone else in your entire life. They truly make you happy and you long to make them happy, your heart gets a weakness feeling when you see them. Your chest gets weak, you get shaky and may sweat around them. You are afraid of saying something stupid and may beat yourself up over something you said that you felt like it came out dumb, though it might not have been stupid. You have told her that you love her/him, passionately and truthfully. You would never lie to her/him, you feel like you can tell her/him anything. You stand by her/his side no matter what happens. You feel like their very existence completes you. Around them, nothing can go wrong, all is right in the world.
For those that have been rejected, but still love somebody: If you are friends with each other now, don't worry about it. If you truly love them, they will see it in your actions and very well may grow to love you. Just don't let go of hope.
For those that are in love, but don't know how to tell her/him: Just tell them. There is no simpler path to take. If you are alread BF/GF, then that is wonderful. Find a nice place to just sit down and talk, just tell them. But if you are not BF/GF, DO NOT COME HEAD ON AND CONFESS TO THEM, THIS IS THE MISTAKE I MADE, WE ARE FRIENDS BUT I DOUBT IT WILL BE ANYTHING MORE. PLEASE, IF YOU DON'T WANT TO END UP LIKE ME, BECOME HER/HIS BF/GF FIRST BEFORE YOU DO ANYTHING!!
Love affects any age. I will repeat this one: Love affects ANY age. I know that some people say things like "Oh he's just 13, he can't love." That isn't true. Some people are more emotionally mature than others. Just because some kids haven't been in love doesn't mean it isn't possible at their young age. I completely encourage all ages to not hide this feeling, telling someone about your love for the person, normally a best friend of the opposite sex is the best option.
There is a lot more I have missed, but the night is aging and I must go to sleep. Thank you for reading.
Alejandra, I love you unconditionally and I always will until the day I die.