What does Selena Gomez mean when she says you are the thunder and im the lightning in her new song Naturally?

Them lyrics are from the song Naturally, and they mean:

Thunder and Lightning nearly always come together and when you think thunder you think lightning.

Selena mean's in Naturally that she's found that special person who belongs with her, like thunder belongs with lightning. It's hard to describe. Lightning comes with thunder so Selena means they are never one with out the other. She's found the thunder to her lightning = she founds the person that belongs with her. III THIINK.