Regret
From Tardis Wiki, the free Doctor Who reference
Choosing to leave her behind in 22nd century England, the First Doctor told Susan Foreman to go forward without regrets, tears or anxieties. (TV: The Dalek Invasion of Earth)
After departing from a giant toyshop which contained an interdimensional doll's house, the Second Doctor was left with a sense of regret that he could never understand. (PROSE: The Celestial Toyshop)
Constance Clarke received a telegram telling her that the Royal Navy regretted to inform her of Lt-Cmdr Henry Clarke's disappearance. (AUDIO: Quicksilver)
After saving a child from being hit by a VW Beetle in 1987 Southport, the Ninth Doctor told David Gee and his wife that "[he'd] regret that in the morning". (PROSE: Have You Seen This Man?)
