Celestia doesn't love.

>Celestia has had a long line of suitors over the years.
>But none of them ever stuck around for long.
>They claimed to love her at first, but they loved the idea of her, Celestia the Princess of the Sun
>They didn't love Celestia the pony

>They weren't gold diggers, or faking their interest in her (most of them anyway)
>But they couldn't handle the reality
>And when their image of the Perfect Pony Princess, who would cater to their every whim, was stripped away
>When they got to see a glimpse underneath the mask she wore, and saw the real her underneath, they didn't like it.

>That she got sad, angry, frustrated, and afraid just like everypony else
>That she wasn't always prim and proper
>That she had responsibilities
>That a crisis could and would happen at any time, and she would spend her days trying to keep her life's work from unraveling at the seams
>Facing horrors that only she can.

>That she would spend the majority of her time in court, listening to the requests, complaints, and demands of her subjects
>Or dealing with the nobility and the bureaucracy.
>Trying to juggle the needs of a kingdom instead of devoting all her attention to romance

>After the first few centuries of romantic failure, she resigned herself to the inevitable
>That love was an ephemeral thing, something she could only experience for a brief time, before it disappeared.

>She accepted less and less when a stallion would declare his love for her
>Knowing that the time would come when they would leave, having never really loved the real her at all.
>She wants to experience the real thing so badly, but it has eluded her all these years.
>When the pain of loss recedes, she lies to herself, that maybe this time, things will be different.
>And she indulges herself in this poor substitute for real love, until the high wears off, and it all comes crashing down again.