Thanks for the replies to this thread. Just to add to this - I think it's also important for your mental well being not to constantly look up a girl you're attracted to on social media.
A quick initial look is fine, but if you keep looking them up (especially if they rejected you/it didn't work out with her) it just makes you feel weak, anxious and can lead to potential oneitis. It takes a lot of self-discipline to resist the temptation to keep looking them up, especially if it was with someone you were really attracted to, but it's best for your mental health if you don't.