Don't forget about them

It's easy to unintentionally drop your other friends at first, but as the hormones settle down, you'll spend more time with your friends.

It's not that I'm gonna unintentionally drop my friends. It's that I'm gonna force myself to choose. I'd much rather have five close friends and no significant other (or one could say all my friends are my significant others) than have one "partner" and no close friends (but still good friends, but not "close")
^That's the best I can describe, sorry that it's kinda vague.

Why would you force yourself to choose between a partner or your closest friends?

Because that's how my mind works.