Chicharito joined the club from Guadalajara and also revealed his shock at Sir Alex Ferguson's side wanting to sign him.
"My dad told me: 'Hey, Manchester United want you,' and I told my dad: 'No way dad, you're teasing me'," he told ESPN.
"One night I was playing video games with the club, with [Wayne] Rooney, and two days later you tell me that the club wants to sign me? I told him: 'No dad, it's not a true. Impossible'.
"[When you join a club like United] it is difficult to find a balance between enjoying it, not getting obsessed over wanting more and thinking that you have already done everything.
"It is like bittersweet. It was all amazing and then on the plane I asked myself: And now what?"