On the subject of detonation:
My understanding of the phenomena is that it occurs because peak pressure and temperature in the cylinder overcome the resistance to detonation of the air / fuel (octane rating) mixture. Detonation occurs AFTER the normal ignition by spark has taken place. In the event, the unburned mixture ahead of the flame front explodes rather than burns. At low RPM the peak pressure is likely to overcome the knock resistance of the fuel more readily simply because the piston is moving slower and therefore the combustion chamber volume is expanding less rapidly.
On the other hand, Pre-ignition is caused by a hot spot and is independent of the normal spark ignition. It may cause pinking in the same way as over-advanced ignition (that's all it is), or detonation does.
Another phenomena, Auto-ignition is akin to how a diesel fires off, from residual heat in the cylinder combined with the extra heat of compression.
The pinking (pinging if you're American) noise we may hear as a result of any of the above is worse on a worn engine because the con-rod bearings get well and truly rattled. To put the extra stresses caused by detonation in perspective, imagine the difference between being pushed hard in the ribs by a little bloke - it might not hurt much and just cause you to be moved out of his way, whereas a swift kick from the same chap definitely would hurt and might even cause a fractured rib or two.
On extremely highly boosted engines (dragsters etc) with turbo-charging and nitrous oxide injection, it is by no means unheard of for conrods to fail in compression, they twist into an S shape, causing the piston to get clouted from below by the crankshaft. This spectacularly results in the innards becoming the outards.....