measure twice, cut once

[bobfish45]

I'm sure most of us have come across that little adage a time or two, my wife has always quoted it to me whenever a shelf, curtain rail or whatever has been put up over the years.
I could have done with her at the garage Sat morning!!!
One new pair of drive shafts going on, drivers side first.
Drivers side first, old one off, measure against the new ones,not much in it but, "yes that's the one", 15 mins later, fitted,"'I'll just give it a try", ramp down, in gear, clutch up,--------------going nowhere, clunking noise underneath
Back up in the air and the inner joint has destroyed the gaiter and was hanging out .
Has anyone guessed yet?
Yes I had fitted the shorter of the two shafts, If I had measured them vertically and taken the play out of the inner joint, I would have seen the few mill difference, instead I had to fit a new inner boot, fit the other shaft miss my meeting with bigfor2 and consider myself a right to**er.
So remember, MEASURE TWICE, CUT ONCE!!!