The Chassam Sofer answers that Moshe saw an opportunity to do more Mitzvot, and although they weren't in front of him (he had to go into Israel to perform them), he still felt the need to perform them, and did what he could to be able to complete them. In contrast, when was the last time we begged anyone to be able to do a Mitzvah? In fact, do we perform all the Mitzvot that we CAN? How many times have we even deliberately walked away from a chance to help someone? We should strive to be like Moshe, and work to appreciate, take advantage of, and especially LEARN about all the opportunities we are given, to do something good both for G-d , for each other, and ultimately for ourselves!