pullup machine: triumph and failure

I made a new discovery: after searching high and low for a pullup—well, pull-down—machine (I first saw one along the Joongnang-cheon during the walk to Uijeongbu) somewhere in my own neighborhood, I finally found one in a little exercise park close to the Han River today, right at the confluence of the Han River and the Tan Creek. No one was using the machine, so I walked up, sat down... and immediately discovered that, unlike the bench-press machine, which requires me to work, the pullup machine is absurdly easy to use. I blasted out thirty scaled-down pullups without any strain at all; I stopped out of boredom, not because I was tired. It might be interesting to try doing the exercise to failure, but I'm in no hurry. Anyway, the machine is there if I want to exercise certain muscle groups, but I wish it had been set to present the user with more of a challenge, especially for an utter weakling like me, who hasn't done a single legitimate pullup in years.