Well, being that I googled in quotes, "how do exoplanets form?" and only pulled up 19 results IN ALL OF GOOGLE mind you...
I thought I'd go ahead and make a little post about it.
Q: How do exoplanets form?
A: They are cooling, very old stars which shrink and die (some are much older than others), ceasing radiating in the visible spectrum, which differentiate their interiors and combine chemically all their elements into molecules making rocks, minerals, life, oil, water and literally every chemical compound that occurs naturally.
The second question which naturally arises from the first:
Q: But stars are not (exo)-planets, they are two different objects, how can one be the other?!
A: It is not that one IS the other, it is that young planets are bright, big and hot, and old ones are dim, small and cold worlds. Humanity calls the young planets "stars", and the old stars "(exo)-planets" thus begins the confusion.
Q: That would mean that all of astronomy's models for stellar evolution and planet formation are wrong then, it means planet formation is stellar evolution itself!
A: Yes. It is that simple.
Q: Why haven't astronomers/astrophysicists been reading this or looking at what you are saying? This is an incredible insight!
A: Maybe they do, but it is much different than what they were taught in school, one cannot be expected to disregard an expansive education in which it took many years to achieve.