I've had a similar experience, where (at the age of about 10) I touched an exposed 120v AC wire on a running water pump, while standing in a muddy field, and I only got a mild vibrating feeling from it.

Depends on how it is wired. Sometimes lights are wired so that the switch comes before the fixture, sometimes after. One of several reasons you should always turn power off at the breaker when fiddling with the wiring, instead of assuming it won't be hot if the switch is off.

  [hot wire]---[switch]---[load]---.
                                   |
  [neutral wire]-------------------+
                                   |
                               [person]
                                   |
                               [ground]

Edit: Or this one...

  [neutral wire]---[load]---[switch]---.
                                       |
  [hot wire]---------------------------+
                                       |
                                   [person]
                                       |
                                   [ground]

the parallel resistance is lower

And once you've turned the power off, test wit with a non-contact voltage detector. A brand name one that's actually been built to UL/CE standards and is subject to actual recalls/etc is under $30. It's a straightforward, pretty much foolproof way to make sure you don't get yourself shocked.

A multimeter is, in theory, a fine alternative but in practice is not. The non-contact detector detects the presence of the fluctuating magnetic field from A/C. A multimeter measures the difference in potential between two points. If you were to, say, have 120V on from same phase on both hot and neutral in an outlet, it would read 0V. If, say, the ground were also not connected then you'd also get 0V testing either against ground. By all accounts there is no voltage in the plug. If, say, each side of the plug were on a different breaker you might think you'd killed the power while it's still live. (Yes, this is based on a true story.) The only way to avoid this is to make sure you have a known good ground to test against. Whereas a non-contact voltage detector immediately lights up like a christmas tree telling you this situation is all sorts of fucked up.

commonly the neutral wire has something like 20vac rms on it for a variety of reasons

if you are ungrounded (due to rubber boots or whatever) your body is in series with your capacitance to ground, and that will commonly give you just a mild vibrating feeling or nothing at all

this 'path of least resistance' thing can be pretty misleading, because if you have two resistors in parallel, the least resistance is always the parallel resistance (i.e. current through both resistors in inverse proportion to their resistances) and not just one resistor or the other

Electricity doesn't take the path of least resistance. It takes all paths. Think of it as a resistor network:

    (+)---[R1]----[R2]-----(-)
               \--[R3]--/

If R1 is sufficiently high, e.g. the light was off but the switch interrupted the neutral side, and you touched the neutral side (i.e. the lamp was between mains and you), then the "path of least resistance" matters: R1 and the parallel set of R2/R3 form a voltage divider, and the smaller the combined resistance of the right part is, the lower the voltage across you.

That voltage is all that matters. If R1 is small enough to be insignificant, e.g. because you're touching mains and R3 isn't a short to ground, the voltage across you will be mains voltage.