tenacious

good at remembering; "a retentive mind"; "tenacious memory"

stubbornly unyielding; "dogged persistence"; "dour determination"; "the most vocal and pertinacious of all the critics"; "a mind not gifted to discover truth but tenacious to hold it"- T.S.Eliot; "men tenacious of opinion"

sticking together; "two coherent sheets"; "tenacious burrs"