The 70-year-old veteran saw the Dhanush and Sonam Kapoor-starrer in celebration of India's victory at the Champions Trophy Sunday night.
"It was a delight. I get so envious after seeing all these wonderful films, and lament and regret that I am not in them, even in a small capacity, for I love the immense talent and finesse that today's cinema with its young brigade brings to the world, " Big B posted on his blog.
The actor also has a few movies in his "to-watch" list.
"I shall be seeing some other unreleased films given to me by Anurag Kashyap, by some talented directors and actors... a joy always, " he wrote.
On the big screen, Amitabh will soon be seen in Prakash Jha's "Satyagraha".