What are some good philosophical mindsets (i.e."Live like there’s no tomorrow, dream as if you’ll live forever.")?

MY favorite and reflective of myself....,

Reality is that which exists outside of your beliefs..

My favorite is this Lady Gaga quote:

"At the end of the day, you won't be happy until you love yourself"

I think it's cool that she is so down to earth with the things that she comes out with... And it's true. This is something I struggled with for a while, always worrying about what other people thought about me, when in the end it is just about how happy you are with yourself. I dunno if that's a mindset or not though lol!