“Twenty years from now you will be more disappointed by the things that you didn’t do than by the ones you did do.” who said?

Mark Tawin

https://quoteinvestigator.com/2011/09/29/you-did/

It's true.  I could have gotten SO MUCH more action from women as a young single guy.  I had so many opportunities that I did not go for.  I certainly regret that much more than anything I actually did.

Hallmark , probably. 

They love trite sentiments.

No one. You've just made that shiit up to try and sound wise lol. Some people be seeing through bullshiit better than others okay.

No one knows for certain. Apparently it is often attributed to Mark Twain but an authority on such things,  Barbara Schmidt, says that it cannot be authenticated because it does not appear in any of his writings. One theory is that H. Jackson Brown, Jr.'s mother penned it in a book that she wrote to him called P.S, I Love You in which the saying appears.

I don't know who said that but I absolutely agree. It's better to pursue your dreams instead of not doing anything. Life is about taking chances in the pursuit of happiness.

Of all the things I said that wasn't one of them 😟.