I see. Thank you for noting that. I did not realize basic search functionality was limited, though I expect it is so to prevent abuse. I would guess that it is likely 'unlocked' upon reaching level 2, which only needs 40 points. You only have 20 comments including this one in the past 3 months your account has existed (1 comment every 4.5 days or so avg.), so you just now hit level 1 with 10 points. Level 2 is reached pretty quickly with a little more participation on the site, though I admit I do not know if it is restricted until level 3 or even 4 but I would not expect it to be so.