Every other trip, I make the mistake of taking too many things and trying to do too much. Generally, I enjoy rangetrips with one or two guns, and a shortlist of things I want to accomplish.
When I take too much, invariably, I
a) forget to bring something (ie. ammo), rendering part of the haul of guns inert
b) get to the range on a crowded day and lack room to spread out my gear
c) fail to complete a task I took gun X there to do in the first place
d) RUN OUT OF TIME
e) Get home tired and perturbed at my screw ups
f) TOO MANY GUNS to clean!