It doesn’t always make sense to buy in bulk.
Buying twenty batteries instead of five makes sense, as long as you’ve got something to put them in. But over-ordering flyers for a one time event just because you might get a better unit price is insanity. The fliers will end up in a bin, and your money in the hands of the printer for no reason.
Same goes for ideas. Rapid fire brainstorming, huge gant charts and methodical step-by-step planning is completely neccessary for certain projects, and totally unnecessary for others.
There is no margin for error or estimation in a space launch, but there is plenty in the first iteration of your website design.
We learn more by testing our ideas than we ever will be hoarding them.