The actress told US Vogue that all she could think about at the ceremony was not repeating Jennifer Lawrence's famous 2013 trip.
She described her thoughts as being: "Don't fall on those stairs. It's not cute if you follow Jennifer Lawrence - it's not cute if you're the second one!"
The 12 Years a Slave star also revealed that she was warned about the intense nature of the awards season.
"Everyone said, 'Brace yourself, Lupita! Keep a granola bar in that clutch of yours!'
"I didn't really understand what they meant, and it was only once it was past that I realised that my body had been holding on by a thread to get through this very intense experience. Nothing can prepare you for awards season.
"The red carpet feels like a war zone, except you cannot fly or fight; you just have to stand there and take it."
Nyong'o went on to say that her sudden fame following her 12 Years a Slave role and subsequent Oscar win has come as a shock.
"It just feels like the entertainment industry exploded into my life," she explained. "People who seemed so distant all of a sudden were right in front of me and recognising me - before I recognised them!
"For a split second I looked behind me to see who they were flashing at - and it was me!
"That was, I think, the beginning of the end of my anonymity."
It was revealed earlier this month that Nyong'o will star in the eagerly anticipated Star Wars: Episode VII, due for release on December 18, 2015.
Lupita Nyong'o's full interview appears in the July issue of US Vogue magazine, which hits newsstands nationwide on June 30 and is available now as a digital download for the iPad, Kindle Fire, NOOK Colour and NOOK Tablet.