My late father sometimes had problems remembering things in his latter days.
Like many folk of his advanced years, there were some good days and some not-so-good.
After a while, I found a way of establishing which was which.
I called it the Emile Heskey Test.
Simple enough; all I had to do when meeting up with Pops was utter these words: "So, what about Emile Heskey?"
Occasionally, the octogenarian couldn't recall who I was referring to, but most of the time he answered thus: "That clown? I can't believe Liverpool paid £11m for a big lump who couldn't hit a barn door..."
Yep, that was one of the many good days.
I found myself recalling the Heskey Test earlier this summer when hearing the new Manchester United manager Louis van Gaal praising Ashley Young following a couple of goals in a training session –sorry, pre-season friendly – against Real Madrid.
This is a bad day, I thought. Surely not another man in the Old Trafford hot-seat who actually believes this fellow (and, Dad, he cost United a lot more than Liverpool paid for Heskey) is good enough to wear a Red Devils shirt.
He doesn't even look up when he attempts to cross the ball, for goodness sake!
Hopefully, after Saturday's home defeat to Swansea, Van Gaal will realise that the boul' Mr Young should be at the top of a long list of players heading for the exit door at Old Trafford.
If not, the veteran Dutchman should prepare for a lot more of the bad days.