I am reading Wikipedia for their definition of "fiber bundle" and it seems to me it used to be a bit more comprehensible. Then I look up "double fibration" and hit a bunch of stuff about Twistor space, like:
and I think - geez! what happened to the geometry? I mean pictures. In general, Wikipedia mathematical definitions are abundantly formal, often failing to give the common sense meaning. For example do they show the picture for Lagrange multipliers? Actually they do, but not the right picture.
Lagrange multipliers find where the optimum valued isotherm touches the constraint for the last time. The key idea being that you can look for where the red and green vectors coincide: