Not correct, lithium ion batteries don't suffer the memory effect and should not degrade over time. All of my previous Android phones still take the same charge as day one. This myth needs to be put to rest.
I don't care whether they do or do not suffer a memory effect, or if they should or should not degrade over time . They do in fact degrade.
At least, that is my experience with multiple batteries. And no, I don't know why, but it happens to me on every phone that I've had, droid 1, Droid 2, galaxy s3, galaxy s5, note 3. I do believe all of them had lithium ion batteries, at least the three Samsung phones did.
I realize that comments on battery life can be very subjective, but when you go from only having to put your phone on a charger at night to not being able to make it through the middle of the afternoon on a consistent basis, and you haven't changed anything or added any new apps, I believe it is safe to say that your battery has degraded for some reason, whether it's because of a memory effect or not.
Maybe they're overheating because I use them too much, or because I live in the south, who knows?
It's not a myth if it's happening to you! Just ask your average iPhone user who's had their phone over 6 months and can't get through half a day without finding a charger, because I know plenty of people in that boat