Is certainty regarding the answer and achieving first place once more after previous success considered arrogance?

Your certainty that Allah will answer your supplication is good, not arrogance, based on the Prophet's (peace and blessings be upon him) saying: "Supplicate to Allah while being certain of the answer." The forms of response vary: your request might be fulfilled, Allah might avert evil from you, or He might save the reward of the supplication for you until the Day of Resurrection, based on the Prophet's (peace and blessings be upon him) saying: "There is no Muslim who supplicates with a supplication that does not involve sin or cutting off ties of kinship, but Allah will grant him one of three things: either He will hasten his supplication for him, or He will store it for him in the Hereafter, or He will avert from him an evil comparable to it." Therefore, supplicate frequently and insistently ask for what you desire, be confident in Allah's bounty, and then be content with what He decrees for you.