[ortek_service]

Yes, I do remember using old thick resistor leads in breadboard. Then trying to insert polystyrene capacitors leads (A bit like with IC sockets and wrong pins types)
But with breadboard, you did at least tend to be able to feel when the leads were too loose, and could remove the bottom and the contact strips to crimp them back up again (or remove snapped-off wire ends!). The real problem is when a complex built circuit stops working, due to a wire getting dislodged or breaking and you've got to go through it all. Might also find that some of the recent cheaper versions don't grip as tight, even when new.