(one) needs to get out more
One has been spending too much time in a sheltered, insular environment or focusing too much on one activity. I think it's great that she loves reading so much, but she really needs to get out more. After working so hard on my guide to English grammar, I find myself analyzing the grammatical correctness of everything I hear or read. I need to get out more.
someone needs to get out more
INFORMALIf you say that someone needs to get out more, you mean that they are boring or that they are spending too much time concentrating on one particular thing. I found myself reading The Inner Game Of Tennis the other day. (I really do need to get out more.) Note: This expression is usually used humorously.