Holt, at 33, is the oldest member of the Villa squad.
"I think it raised a few eyebrows because I'd come from not playing in the Championship to a big Premier League club like Villa," he told the Telegraph.
"The manager knows what he gets from me. I'm under no illusions, if there had been a big transfer fee involved it probably wouldn't have happened. He knows I'll work hard and want to win. I hate losing.
"I love walking into a ground and getting abuse. I thrive on it. I like the banter I get on Twitter - the people give me this and I give a little back.
"I'm the world's worst. I'll go to Carlisle games and I'll be on the terraces watching it and I shout stuff and then I think, 'Grant what are you doing'?
"But that's football, everyone's got their opinion. Wouldn't it be boring if everyone was the same and thought 'isn't he a great player?'."