People often can't stick to their plans because life is full of surprises. Things like sudden health issues or emergencies can pop up out of nowhere. Sometimes, work or school commitments become more important and take over. Even the weather can mess up outdoor plans. And then there are family responsibilities that might need immediate attention, making it hard to follow through with original plans.

Sometimes, people can't follow their plans because they lose motivation or discipline. It's easy to get distracted by things like social media or entertainment. Procrastination can also be a big problem, leading to delays and missed deadlines. If people set goals that are too hard to reach, they might feel discouraged and give up on their plans altogether.

People's plans can change because their priorities shift over time. As they grow, their interests might change, leading them to reevaluate their goals. New opportunities can also come up, requiring a change in plans. Sometimes, advice from mentors or external influences can alter their direction. Adapting to new circumstances is often necessary, which means plans need to be flexible.