We live in a dual (relative) world.
Everything exists thanks to its opposite: light/dark, up/down, front/back, big/small, rich/poor, healthy/sick, etc.
It is impossible to enjoy perfect health if one doesn't know what the opposite of perfect health is, if one cannot experience sickness. It is impossible to enjoy riches if one cannot experience poverty.
Let us assume that it is possible for an experienced I-M user to get
EVERYTHING what he wants,
ANYTIME.
He will always have what he wants, so we can assume that this person strives for a perfect health, "enough" money, beautiful relationships, etc.
It would be illogically to strive for the opposite (sickness, poverty, loneliness).
Suppose this person wants to get filthy rich, so he applies I-M.
Even if that person has all the money of the world, he isn't capable of enjoy it to its full extent, unless he can experience poverty. The problem is: by applying I-M to get rich, poverty is excluded as an option (you cannot be rich and poor).
This applies to all things you intend: how can you appreciate a perfect health if you never were/are sick?
How can you be happy if you never were/are unhappy?
The fact is: people who apply I-M are not satisfied with their life. They want something else.
I believe that if you are serious about personal development, it is much better to live your life as it presents itself to you, because everything that happens in your life has a meaning for you.
I don't see any reason why you should use I-M, because things that you consider now as "bad", may have a positive effect on your life in the future.
So, despite what most people here say, it is my conviction that applying I-M will have a bad effect on your personal development.
I consider I-M as a cheat code in this life "game".
According to
Wikipedia, "cheat codes are by definition, considered cheating and most serious players only use them for experimentation, if at all".