The first Shinkansen departed at 10am on 1st October 1964. There is a wonderful article on its history (here). Apologies if the link is white, it's beyond our control. The shinkansen cut a previous 7 hour journey to just 4 hours; a life-changing difference that made even a day trip from Osaka to Tokyo a possibility.
I've only ever been late on a shinkansen once. The weather was awful and British trains would have simply given up, instead advising people not to travel. But our shinkansen duly arrived just 15 minutes late. All that extra time was taken up by the guard apologising profusely. In the evening it was on the main news - various shinkansen had even been delayed by 15 minutes. Interviews were of course sought from Japan Rail to explain these dreadful affairs.
The third remarkable feature after speed and punctuality is frequency. Imagine a peak time London-Edinburgh timetable of one train almost every 5 minutes. It's not that frequent all of the day of course, but there are over 300 trains per day shuttling between Tokyo and Osaka from dawn till dusk.