overplay one's hand
overbold
overshoot
think one's shit doesn't stink
overeffusiveness
overhardy
overhold
overoptimistically
overfastidiousness
overassertiveness
overguesstimate
overween
overambitiousness
overambition
superestimate
audacity
overdaring
overattentiveness
overstand
knock-me-down
oversanguine
get one's knickers in a twist
overpoweringness
forset
a bridge too far
blow out of proportion
overintensity
overdo
overassertive
hardihood
overratedly
overburn
overobjectify
compel
gunner
overdramatically
overdrift
overeagerness
overboldly
overratedness
overesteem
overreachingly
overassertively
overexcitability
overgoing
overhastiness
overcompetitiveness
overdoneness
over-egg
high and mighty