There are many things that we used to be able to do that are no longer possible, or at least no longer easy or simple.
I could also include things that you used to be able to get away with, even if you did them accidentally, like running a red light or pushing your luck just a bit on a yellow. Used to be you only had to worry if there was a cop watching. Now you see that strobe-like flash and three days later you get a ticket in the mail along with complete photographic documentation of the event.
I used to be able to put $40 worth of gas in my truck (or $10 or $20). Now it's almost impossible. I can put in $39.98 or $40.02, but for the life of me I cannot get the pump to stop on exactly $40.
It might be that my reaction time is not what it used to be, but the darn pump runs so fast that there are probably only a few people in the world with reflexes quick enough to stop it on a predetermined amount. It drives me batty when it comes time to do the books.
All those stray cents and odd numbers just add to the stress.