We have been created from love for love. God loves us so much, that we are literally overflowing with His love, so He commanded us to love our neighbor. Imagine someone saying they will pay for $100 of gas, but you can only use it once. Instead of using all $100, you only use the $20 necessary to fill up your tank and waste the rest instead of offering to fill up the car behind you or next to you. That’s the equivalent of wasting God’s love by not sharing it.
God didn’t say to love only our families or friends. He said to love our neighbor. Sometimes our neighbors are bothersome, sometimes annoying, sometimes worse than that. God didn’t say to love them only when it was convenient or when we wanted to. He said to love them with the implication that we are supposed to do it always. Do it.