If you wanted to give a dozen oranges to your neighbor as an expression of love, you would need to have a dozen oranges. If you intended to buy a new car for your parents to show your gratitude to them, you would need to have the funds to purchase the car. Likewise, you can't give love away to others if you don't have any for yourself. You can't show respect for others if you lack self-respect. You can't give happiness away if you feel unhappy.
The concept is simplified by a description of squeezing an orange. When you squeeze an orange, you'll always get orange juice to come out. This is true regardless of who does the squeezing, what time of day you squeeze, what instrument you use to squeeze, or what circumstances surround the orange-squeezing. What comes out is what's inside. The same logic applies to you.
What do you have inside? taken from 10 Secrets for Success and Inner Peace by Wayne Dyer