I do it for self preservation. You can't show vulnerability or provide too much information. It will be used against you, especially when you're not around. You can't get too close or you'll get burnt; but if you don't mingle with the community, you'll feel cold. Being very private but lying when you have to be open about somethings is a good medium.
Private/mysterious 98% of the time (talking about anything, especially about their life but not yourself except vaguely), 1% lies/lie by omission that would identify you (qabiil, degree focus, neighbourhood you live in, who your parents are, vacations), 1% truths that aren't serious (what sports you watch, which uni I went to, views within the Somali Overton Window, how you like your coffee, 1 or 2 extreme views I hold with conviction even though I hold many while still appearing to be very sensible to him overall which makes you appear even more mysterious to them).
With Somalis, you must shape your interactions through delicate calculation. For sensitive information like clan, I make sure to pick one that fits their personality: is he a rabid qabiilist (pick his clan) or just a qabiilist (pick a clan he would hate) or would he not care (pick any random clan)?
So far, without sharing anything about myself: I have seen him cry multiple times, he shared the times he cheated on his wife, opened up about his serious crimes as a kid in the 90s he got away with, have seen him talk to himself, etc.
I'm convinced there is a crazy spectrum from 1-10 and everyone has a score. He is maybe a 3.