There are times when you start feeling that life is meaningless and mind goes totally blank. It could come about due to boredom, frustration, recurring problems or failure to achieve targets. It could also be due to financial struggles, career struggles or health problems. Some may be disgusted with the corruption, nepotism, and mismanagement seen around.
You may think the fault is with the system and most often we can do nothing to change it. Sometimes, an existential crisis could be triggered by anxieties and concerns about daily life and they can be overcome by reading motivational books and quotations.
"Be joyful, though you have considered all the facts." - Wendell Berry