DD is 2.5yrs and I'm a lone parent, although I get some help from my parents sometimes.
My Mum is adament that, whenever I have to tell DD to do/not to do something, I should always explain to her why.
Obviously I do so whenever it is feasible - but I'm worried that at her age she's going to get baffled/bored/confused by long winded "because you might/there's a slight chance that/because I'd like you to so that I can/etc" conversations every 5 minutes, and to be honest it's getting a little draining as she is now starting to challenge me for explainations when I'm asking her to do things - not a problem so much at home, but slightly inconvenient when she is lying on the floor in the middle of the very busy fast-pay till aisle while I'm trying to work the sodding machine and refusing to move.
AIBU in thinking that, sometimes, 'no' just has to mean 'no', and 'because I've asked you to' is a reasonable explaination under some circumstances. My Mum thinks I am, and will pull me up on it if I'm caught doing that when they're around!