I do not know how old the strings on my electric guitar were but they came with it when I bought it second-hand a couple of years ago. I had been finding that it went out of tune quite quickly and kept intending to change the strings but finally got round to making good on my plans yesterday. The first proper outing was at church this morning and, while new strings have some tuning issues of their own, it was a definite improvement.
As well as improving tuning, new strings have a harmonious ring to them that I keep forgetting about until I finally get round to breaking out another set, confirming my belief that it is the most elementary thing to check on any stringed instrument that seems to seem a touch dead and hard to play. It makes the guitar feel lighter, sound sweet and play more easily. I wonder what should be next for the new string upgrade in my collection?