There comes a time when somethings in life come to a standstill. They cease to serve any purpose in life. They cease to excite you, they no longer help you grow. Before that feeling sinks in, it is better to move on, else you will be caught in stagnation. Like a quicksand, the harder you try to move out, the deeper it pulls you in. someone very rightly said, the only constant thing in the world is change.
Change for better is good, but no one knows if the change will make you better off or worse. That element of uncertainty will always loom, but sometimes an unpredictability is better than the the certainty which does not take you forward.
Before the feeling of stagnation overpowers you, make a move, because the ability to give up on something that does not add meaning to your dreams, aspirations or future goals requires real courage and a tough decision.
In terms of economics, this can be correlated to the law of diminishing marginal utility. The more you do it, the lesser satisfaction you gain out of it (the economists may beg to differ if i used the incorrect law here). Life is too short to carry regrets. After all, life is just once, and it is short. Why restrict to the set definitions, roles,rules, learnings, experiences.
Keep moving, keep learning and keep dreaming !