How did I manage to not be hurt after accidentally making an electric contact between mains wires?
HUGE WARNING Toying with mains can cause electrocution, injuries, impairment, fires, damage to property. Protect yourself. Don't work on live mains unless you're qualified to do so and follow all the required safety practices

Your mileage may vary greatly depending on a lot of factors which together determine whether you have low enough resistance in the circuit formed by phase wire, your body and either neutral or ground. Your body resistance may vary within some range and that sometimes can make a difference. In this specific case the most likely factor is that the DuPont wires you used were rather thin and also the contact surface between them and the mains was also rather small and that together gave you a rather high resistance circuit so the current was rather low and not enough to cause serious damage.

I have a neat story of what once happened in a lower resistance scenario. Long ago I accidentally touched with the same finger both phase and neutral terminals of an electric outlet with cover off and live wires connected. The voltage was 220 volts AC. 10 amperes automatic breaker tripped immediately and I've got a two millimeters deep and about five millimeters wide burn to carbon color on my finger. Automatic breakers take dozens of minutes to trip if current is only slightly higher than cut-off value (20% if I recall correctly - so it'd be 12 amperes for about an hour in this example) and tripping immediately only happens when current is much, much higher than the cut-off value. This time it only went through part of a single finger and burnt skin to carbon color. Should it go through body it would most certainly be fatal and you would not get this answer from me.