No one twisted my arm, but I shall tell you how I count laps while I swim. My method is sufficiently variable that it won't become rote for a while. It’s relatively easy to maintain an accurate lap count. (I used to use a device, worn at belt-level, to count laps, but its battery wore out, and I have become more concerned with knowing exactly what count I’m up to, in order to pace myself.) I like my game, because it makes me scour my memory to try to find vocabulary.
The pool is 25 yards long, so I count groups of four laps (100 yard distances). In the first four laps, I think of a word beginning with ‘a.’ In the next four, ‘b.’ And so on.
In each four-lap group, the first vowel (ignoring the first letter, which may also be a vowel), varies on each lap. It is successively: ‘a’ ‘e’ ‘i’ and then either ‘o’ or ‘u.’
Additionally, I pick one letter for each swim and require that letter to appear in every word. If it’s an easy letter like ‘s,’ I try to find words containing two or three or even four of this letter. (For example: “assists.”) Now suppose that ‘v’ is my special letter. I might use these words to count laps:
Avarice, avenue, arriviste, avow; brave, breve, bivalve, bloviate...
When ‘q’ is the first letter, I ‘assume’ the ‘u,’ so my words might be: quaver, questive (ick), quiver, quo? (I can’t always think of a word.)
I also like to find very short words. If I’m desperate, I will use names and other proper nouns and even foreign words. After all, it’s my swim.