O/T Yet another "senior moment"

Despatched by SWMBO to see why the cruise control was not working on her Jazz and discovered that the actuating wire that connects to the throttle cable had parted company so decided to replace with a short length of 4mm ball chain.....
Ok all goes well I held the throttle open with a small piece of timber to give me some slack in the cable to do the work.... Job finished I forgot about the small timber "sprag" and started up, the engine raced, I tapped the throttle apparently just enough to take tension off the sprag which fell out of the place it was put.
Backed out for a test run and discovered that I can't engage second gear.... I endure a tirade from SWMBO who insists that it was all ok untill I touched it, I try to explain that I did nothing to the gearbox...... Ok back into the workshop to see what is going on and to my total humiliation and embarrasement discover the little wooden sprag wedged on top of the G/B exactly in position to stop the gizmo moving into 2nd gear....
I'm gonna give up this do it yourself servicing, and thanks for being so kind as to not have told the forum about this before as I know some of you must know as SWMBO spent the rest of the day on the phone ranting about it to all her rellies and even the talking clock got an earfull....