This is a day of 50-year-old flashbacks and anniversaries. The minute-by-minute replay of CBS’s coverage of the John F. Kennedy assassination and aftermath continues to be streamed on cbsnews.com, just as CBS broadcast it on this day in 1963. Also today in 1963, Doctor Who premiered in England, and BBC America marks the occasion by presenting the newest Doctor Who episode in a 50-years-later global telecast at 2:50 p.m. ET. And tonight on Comedy Central, Bill Cosby stars in his first standup comedy concert in 30 years. So how does that tie in to a golden anniversary? Because 1963 also was the year in which Cosby released his first comedy LP, Bill Cosby Is a Very Funny Fellow Right! – which, like many delighted youngsters my age, I memorized from start to finish. So how does Cosby, now 76, fare in his return to the solo standup spotlight?  Other than that he does a lot more sitdown than standup, he hasn’t missed a beat – and, like Bob Newhart and the late Jack Benny, gets more out of a pause than any other comic. He also nails it by providing some inspired comedy thesis statements – for example, “Chess is marriage” – then  proving them with a series of sharp observation. Fifty years later, Bill Cosby is a very funny fellow. Right? Riiiiight!