When you have a new idea, it is quite difficult to avoid having all your following thoughts gravitate around it.
If a new slogan comes to you in the middle of the night, all the successive iterations will just be slight variations.
If you think at a solution for a problem you have had for a while, you will expand and stretch the solution until it gets good enough to actually cover at least a small part of the problem.
If the process you have just implemented has proven successful, you will use it until it is too late to understand it is no longer up-to-date.
A possible way around this could be to ask different people to come up with a new idea. Or to foster an environment in which it is normal that different people come up with a variety of new ideas. If you match with a process that clearly defines what gets picked, what gets postponed and what gets rejected, you have a winning machine.