Answering Amen with All Your Strength
The decrees of a person's whole life are torn up for one who answers Amen, Yehei Shemei Rabba with full strength.
The Gemara promises that a person who answers Amen, Yehei Shemei Rabba Mevorach with his full strength will have every decree of seventy years against him torn up. In Ma'adanei Yom Tov, Rav Heller offers two readings of the prayer. One treats it as two requests: that the Divine Name Yud-Hay be made whole through the redemption, and that it be blessed. The other, that of the Tosafos, treats it as a single prayer, that His great Name be blessed. Rashi understood the seventy years as the decrees from a person's youth. Rav Heller prefers to take them as a whole lifetime, since the pasuk in Tehillim describes seventy years as the span of life. In Divrei Chamudos he adds that the two readings carry a practical difference about whether one may pause within the phrase, and that, after the Beis Yosef, one should not stop between Olmaya and Yisbarach.
Source: Ma'adanei Yom Tov and Divrei Chamudos on the Rosh, Berachos 3:19
At your next Kaddish, put your full attention into the response. Face the words, say them out loud and slowly, and do not rush to the next line. Imagine each Amen as a request that touches your whole life, not only the day ahead. If you can, do this at every Kaddish this week, even in a quiet shul. You will find that something simple and short can leave you more awake for the rest of the tefillah.