For example, once I hit a certain one rep max, to do it again, another day isn’t very interesting to me?

For example lifting up the 400 pound sandbag; I’ve already done it, now it no longer interest me? I did it yesterday, felt good about it. I did it again today, no real feeling about doing it?

Lesson:

Once you do it once, don’t do it again the same way!

Or—

We always must be pushing our one repetition maximums — until no end?|