Keanu Reeves was reported last night to be embroiled in a romance with Diane Keaton, the actress who is nearly 20 years his senior. Reeves, 40, was said to have dumped actress girlfriend Lynn Collins, 28, to date the 59-yearold Oscar winner. Reeves met Miss Keaton when they appeared together in the 2003 comedy Something's Gotta Give. He began dating Miss Collins three months ago after they met on the set of the forthcoming drama Il Mare. A friend told the U.S. magazine Star that Reeves was 'hit hard' by turning 40 last year. Breaking up with Miss Collins 'kind...