Tapping in and tapping out -- it's a simple act that has defined a generation of public transport usage.

But one commuter wasn't satisfied by the usual amount of tapping needed for one trip.

Instead, a video posted on All Singapore Stuff on May 18 showed a man continuously tapping in and out of the gantry, supposedly at Outram Park MRT Station.

The video has since gathered more than 1,700 shares and 700 comments.

40 taps in 2.5 minutes

All in all, the two-minute-34-second video showed the man tapping in 20 times and tapping out another 20 times -- making for a remarkable 40 taps in total.

With the video starting mid-way through the man's tapping marathon and ending before he was done, we are left to speculate the true extent to his endurance.

Here's a snippet of the incident:

And here is the man a minute later, seemingly caught in an endless cycle of tapping:

It's also noteworthy that throughout the length of the video, he avoided using the gantry normally reserved for commuters with disabilities or large baggage.

Why?

While we may never know the intentions of the man's compulsive tapping, that didn't stop commenters on the video from speculating, with one commenter positing that he was sleepwalking:

Another possibility is that apart from testing the limits of the human spirit, the man was also testing the limits of his transport card.

Or the MRT gantry.

Pattern to his tapping

However, there also seems to be a pattern in the man's tapping.

He starts with the outer-most gantry (excluding the larger reserved gantry), and goes down three gantries to tap out.

He then proceeds two gantries up to tap back in, before tapping out one gantry down.

This pattern is repeated ten times throughout the video.

Here it is in full:

There was also one instance where the man almost broke the pattern, but he corrected himself at the last minute:

Top image from All Singapore Stuff Facebook