In life we cast something which is not precious or even if it is precious not to the extent where it takes the life of the person whom we cast. We seldom take such risks, unless we are mentally and intellectually crazy and fanatical.
Abhimanyu was cast by Yudhdthira in the battle field not because he was a burden in the war field, rather he was the one who would shape the positive future of Hastinapura. The stakes were high. It was victory at the cost of life, or life at the cost of the complete routing of the Pandava army, including the capture of Yudhishthira.
Abhimanyu feeling the tension of the moment, wanted to take the burden of becoming the cause of relief to the pandavas. The choice was between a conscious present and an unconscious future, both being opposite of each other .
The eventuality did occur, Abhimanyu was brutally killed, but not before damaging the Kuru army to an irreparable extent.
Some people in this world are difficult to forget. They are unforgettable because of their nastiness like Ravana whose name made people cry, and others are unforgettable due to their mind-blowing achievements. Arjuna belonged to the latter category .He was a person who brought happiness to the lives of many.
People like Abhimanyu are like hot sugar cane, you can't drink the hot sugar cane and can't even resist the temptation to taste. Abhimanyu was the person who made people cry with joy pride and gratitude.
In life for creating lasting impressions in war like situations, we will be forced to have more Abhimanyus, since Arjuna's of our life will need to fight the battle elsewhere. We can hope that our Arjuna always be with us, but the battle of life may not allow us that privilege, and we may be forced to make a decision to be an Abhimanyu or a leader like Yudhisthira-- who is forced to send his dear and near one in battle knowing clearly the consequences of such a decision.
In Mahabharata Arjuna is the greatest hero, but Abhimanyu is the one who was willing to be put under the power of fire, so that others could have better resources to continue the battle of life and be victorious and for the battle to continue