imo replacing UPI with cash may not be as seamless but surely you become more aware of how much you spend and where you spend and may lead to lessened expenses.
Definitely this exercise is worth giving a shot
Try writing program which prints its own source code: a Quine
so print("print(...)") will output: print(...) and not the original: print("print(...)").
Therefore adding more print statements won't do it.
here is an example for a quine:
s = 's = %r\nprint(s %% s)'
print(s % s)