Being an urban 21-year-old, I do most of my transactions on petty cash for some meals and snacks. Otherwise, for some drinks and most other services I always present them with some form of virtual currency. I hold a debit card, along with PayTM account - the amazing PayPal of India wallet - for completing transactions over Rs. 300 (~$5). I haven't felt any extra heat about the deficiency of cash with me.
They only time I stood to use an ATM, after the announcement, was when my parents were traveling to a small pilgrimage, for which they wanted some emergency cash that they could carry with them. My mother and I went to the neighborhood ATMs which were either not functioning, without any cash available, or already having a long line of people. It was for my good luck that I found an ATM that was just being loaded. I was the 4th person to get into the ATM, later grew to a 40+ person line. But otherwise, I frequently see long lines of more than 50+ in front of any functioning ATM, where ever it may be. Sure, the lines are long, there's no need to panic unless you need a certain amount of cash urgently, which is rare. I can hardly rationally think it through why so many urban dwellers need cash.
The long lines to the banks are also unprecedented as the deposition of 500s and 1000s can be done later when the lines are shorter. Until then we can use the demonetised units at the applicable counters, such as gas stations and grocery stores.
I like the intention of the government. I'm looking forward to the policy changes (GST and UPI) that would ensure that this step would not need to be taken anytime in the future. Only with such policy changes can the objectives of this exercise be met. So my opinions are reserved until the next budget, March 2017.