Strings: bright for 3 days and then...

Hi guys,
is it just me or every time a new set of strings is put on a ukulele (or another stringed instrument) they are very 'bright' and with a lot of tone during the first 2-3 days and then they lose a lot, setting on a tone that is still good and that is probably going to remain until the strings are in good quality, but still different from the very very first strums of the first days?

Any of you experienced that too? Or is it just me?
And if it is true, why do you think is so? is because of the stretching that occurs at the beginning?

Just curious...

if you want to throw your ideas, please join the thread

No, it's not just you but not every time for me.
I found that especially fluorocarbon give me that impression. Put it on uke and they sound really marvellous, but some days after I found that tone has changed.
Still like, but not the "wow" effect of first strums.

I personally think this is because of the stretching. Stretching makes strings tighter and stiffier and less-resonant.
Even the "feel" of the string change just after a few days.
But I don't know if it is just my ears (and my hands) or if is real.

Strings change tone. Definitely. I put a new set of Nylguts on a tenor last week and I quite liked the new sound but as usual there was no stability. By the time they were stable the tone had changed.

We've got it easy really. Serious steel string guitarists change strings every week. 2 weeks max.
Sure you can get away with not changing steel strings for a lot longer than that but steel strings lose their sparkle rather quickly.

Anthony