Pair programming is the stupidest invention that ever appeared in IT.
As far a I am concern, someone saying that they like it is an indication that the person is not a very good developer in the first place, as it indicates that the person does not have enough confidence to do the job and be responsible for the result, that they need someone to tell them what to do or to constantly confirm that they are on the right path.
It is not a secret that main drivers behind pair programming are “body shops” (e.g. Pivotal Labs or Thoughtworks), insisting on 100% pairing — companies “selling” people to other companies for projects. I.e. someone who charge for “time and material”, not for “the job done well”.
PS And yes, I spent couple month in a company that mandated pair programming. Never again.