志大才疏

1.have great ambition but little talent; have grandiose aims but puny abilities; ambitious but incompetent; have ability unequal to the great task one sets oneself; have capacities not commensurate with one's vaulting ambitions; have high aspirations but little ability; have high ambition [aspirations] but no real ability; high in aim but low-rate in execution; Such noble aspirations call for abilities which he does not have.