Sudden flash of pain after 5 years

I lost my toes over 5 years ago. I was blessed with zero pain left past the first few weeks after it happened.

But today at work, I was giving a presentation and got literally got knocked off my feet by 2 seconds of what felt like me touching a high-voltage line with my left foot.

It was intensively painful and caught me completely off guard. It came full on and went away almost as fast, but it lasted long enough to drop me on my knees in front of all my colleagues - a few of whom had no idea I'm missing bits and wondered what I just did that for.

Anyhow, it was just 2 seconds and then everything went back to normal. But I have no idea what happened after so many problem-free years. Maybe a nerve ending finally gave, or a nerve got pinched or something?

I'm really hoping it was a one-off, because I sure don't need that to happen again. It's not so much the pain rather than the total surprise. I'm a bit scared that it might happen again. It would be a major downer if I started having unpredictable bouts of pain after thinking I had been magically spared for so long...