For those that knew Dumbledore and his obsession with those yellow muggle sweets, it had always been a cause of wonder for them. Why would Dumbledore, known as the one that You-Know-Who feared, love a muggle sweet?
Nobody is quite sure where the rumor that the reason he offered it to people was because it had a calming potion in it. It had been long before the boy-who-lived's time, far before the marauders were born into this world. However, through rumors and just the general feeling at Hogwarts, people avoided eating Dumbledore's lemon drops. It had, unknowingly, been passed through generations of students.
There were some of the strangest rumors circling around Albus's lemon drops. Such as, lemon drops being an old lover's favorite sweet. One that had come about from the marauder's age (he had no doubts it would have to be a Potter) was that he was trying to seduce Minerva with them. There had been speculations he merely wanted to feel young again, and sucked on the candy to make himself feel as though he were a child once more. His friend, Flamel, liked the one in which students thought he had mixed the Elixir of Life into the sweet, which was why he was so old.
Dumbledore got quite a few laughs at the rumors, but no one asked him for an explanation, all wary of what the answer might be. No one asked, simply avoided the lemon drops as if the plague was following them.
It seemed there was an unspoken rule everyone would refuse his lemon drops and never, ever ask why they should do such a thing. It could not, however, be possible that he simply liked the lemon sweets.
The secret would come out during his time as a portrait, sitting in what used to be his office. As it happened, the answer had come from a question from Arthur Weasley himself.
"Professor Dumbledore," he asked in his annual visit to the late headmaster's portrait, "what do you believe is the best muggle invention?"
Dumbledore replied instantly. "The lemon drop, of course."
That brought silence, a shocked Arthur Weasley gaping at a portrait. In the back of his mind, he realized a sneering smirk had appeared on Severus Snape's portrait, but all he could focus on was the fact that the headmaster had just mentioned the forbidden!
Mr. Weasley fled the premises, vowing to himself to never speak to the once-headmaster of the subject ever again. Dumbledore, however, sighed.
"Why is it so hard for people to believe I simply like the sweet?"
Manipulative Dumbledore? Umm, no. This comes from reading too many of those stories...