Q. Re- question (3143) above regarding someone undergoing major surgery during Sefira that likely won't be able to count at least one day of Sefira.
How about someone that because of his bad memory hasn't yet in his life completed Sefira. Should he count with a brocho?
A. On a similar shaila in our Responsa Minchas Aviv (p. 70) regarding a middle aged salesman who constantly travels and was never able to count a complete Sefira, we wrote that following the opinions mentioned above and adding that since at the present time he is aware and does remember Sefira, on mitzvos that depend on knowledge, there is a 'chazaka' that he likely will continue to remember, if he sets his mind to do so.
On question 784, regarding someone sentenced to death during sefira, if he can count with a bracha, we wrote: "Chida (Avodas Hakodesh 7: 217) and others maintain that if one omitted counting one day of sefira, retroactively all the brochos recited would be considered in vain Accordingly it would befit that someone who knows that he won't be able to finish the Sefira, or will miss one day due to surgery or similar irrepressible situation, should listen to someone else's brocho. However most Poskim disagree with the notion that the blessings would become retroactively a brocho levatala, since at that time he was still counting properly. Therefore one can recite the brocho of sefira until the day he misses. (Kinas Sofrim, Piskey Teshuvos 489: 22, Mekadesh Yisroel Sefira 27, Minchas Oviv et. al.)"
However, in our days this shaila is already obsolete, since practically everyone has a cell phone or computing device and can be remembered daily to count Sefira several times a day. On Shabbos he can ask others to remind him, or place signs in his abode.
Horav Shlomo Miller's Shlit'a opinion is similar.
Rabbi A. Bartfeld as advised by Horav Shlomo Miller and Horav Aharon Miller Shlit'a