In business Leo should not rely on the experience of other people and general ideas about this or that. If you do not make sure that the information you have is correct, the wrong data may seriously let you down. You should trust, but check (the latter is more important), though there is no need of becoming a paranoid. You may run some risk, only if you are completely ready for it.
Do not trust your memory too much - it may play a bad trick and fail you one day, putting you into a most embarrassing situation. You should put down telephone numbers, names, addresses in the same notebook, later making a copy of it. You should also copy all important information, especially financial.