Congratulations, Mr. Holdren-Radcliffe. Photo: Matthew Murphy I hadn’t anticipated getting married to Daniel Radcliffe. But as my friend and I located our seats for Every Brilliant Thing — the solo hit by Duncan Macmillan, with Jonny Donahoe, that’s been trekking from Fringe circuits to regional theaters to big commercial productions over the past 13 years — there he was, crouching in Row H, chatting with a couple whose seats were next to ours. The Hudson Theatre was buzzing with more than the