The 37-year-old former Little Britain star said he's a bit of a daydreamer and it could cause problems for him.
On The Rob Brydon Show, he said, 'People see my impressions as a great skill and I am flattered, but there are things I can't do that everyone else can.
'I can do funny voices and funny faces but I can't drive. I am a bit of a daydreamer. I am not joking, sometimes if I go for a wee I am there for 15 minutes before I remember to go.
'My mind just drifts. I am worried I'll be there driving along and I'll go, 'Oh yeah, that Topic bar I ate was a bit smaller than they used to be.' And BAM, SMASH, it's James Dean all over again.'