Well, thanks to everyone. The truth is that what I’m explaining is real, but some people don't believe it. According to some, I made it up, or even people who have experienced seismic tremors or earthquakes haven’t had the sensation I described. Well, I’m fine, I don’t have anxiety, but I still feel that sensation, especially when I'm sitting anywhere.
The comment about observing a glass of water has been very encouraging. Thank you for the simple idea.