McLaren test driver with a DTM career does not understand why Hamilton would swap McLaren for Mercedes.
Throughout Briton Hamilton's six-year racing tenure with McLaren, countryman Paffett, now 31, has split his DTM career with his F1 testing role.
McLaren for Mercedes.
"Some drivers move for their own certain reasons," said Paffett. "I think a few of the times they move people don't understand it and I don't understand this one.
"I knew Lewis very well, I used to kart with him when he was ten years old. Lewis has solely been focused on winning, that is his aim.
"He wants to break records, he wants to win the most championships, win the most races and I see his best place to do that at McLaren. But obviously he wasn't comfortable there anymore or he fancied a new challenge," he added.
Paffett's comments are interesting, as for his entire McLaren career, he has also driven for Mercedes in DTM, the premier German touring car series.
"Mercedes are a big manufacturer and they are putting a lot of effort into their F1 team," he said.
"I'm sure they will get better, but I don't think this year Lewis is going to be in a better position than he would be with McLaren."