Extremely sensitive movement...is this normal?

[glimmer]

Hi everyone,

First off, Happy New Year to everyone on TRF...

I have a question with regards to a recently acquired 1601-4 Datejust. The serial number dates it to 1970 or 1971 and has just been recently serviced. It is different from my other watches in that in order to get the movement going again after it has stopped for a couple of days, all it takes it one shake and the second hand moves back to life. Is this normal? I'm not too familiar with movements but somehow I think that something might be very sensitive with this particular watch, is it just the age or the particular movement that makes it easy to start up again?

Any advice would be much appreciated...