There's a lot of truth to this! If you're tickling someone who does not have our interest, a minute is a long time! I was tickling someone quite a while ago and had them tied up so I could do pretty much anything I wanted to. So, I told them I was going to tickle them for a minute straight, non stop, then 2, then 3, etc, etc. Of course they were freaking out, but hey, we were both young and I didn't care back then. So I started tickling them. I think it was their pits and I was watching the timer. 15 seconds, 30, 45... I started thinking, holy shit, this is a long time! I'm sure they were thinking that at 15! But, anyway, I finally stopped at a minute. They were toast! I actually felt bad for them. But not bad enough not to tease them by asking them if they were ready for 2 minutes!
I didn't do that, but the look of horror on their face was funny!
But the point is, people don't realize the loss of the sensation of time when you're being tickled if you're not used to it. Even if I tickle someone now, I may tickle them for quite a while, but it's not non-stop. There are breaks. And I will move around the body, tickling different spots.