The idea that "life begins at 40" is a common phrase that suggests that people's lives and opportunities really start to flourish once they reach the age of 40. However, the idea is a bit of a cliche and this phrase does not necessarily hold true for everyone.
One's experiences and opportunities in life can change at any age and it depends on the individual's circumstances, goals, and perspective. Some people may find that their life really begins to take off in their 40s, while others may not experience significant changes until later in life, or may have already have lived a fulfilling life before 40.
It's important to remember that life is a journey and it's not limited to specific age milestones. Each phase of life has its own set of challenges and opportunities, and it's important to make the most of each stage.
It's also important to remember that age is just a number and it's never too late to pursue new goals, try new things, or make changes in your life. Whether you're 40 or not, life is what you make of it and it's important to live in the present and make the most of every opportunity that comes your way.