Today is the 14th of the Iyyar, exactly one month after the 14th of Nisan, which is the day on which the Torah instructed our ancestors to offer the Pesah/Passover sacrifice. Why is this day significant? It is referred to as Pesah Sheni, "the second Passover," and mentioned in the Torah as the day one which those who missed the Pesah sacrifice in Nisan get a second chance:
אִישׁ אִישׁ כִּי-יִהְיֶה-טָמֵא לָנֶפֶשׁ אוֹ בְדֶרֶךְ רְחֹקָה לָכֶם, אוֹ לְדֹרֹתֵיכֶם, וְעָשָׂה פֶסַח, לַיהוָה. בַּחֹדֶשׁ הַשֵּׁנִי בְּאַרְבָּעָה עָשָׂר יוֹם, בֵּין הָעַרְבַּיִם--יַעֲשׂוּ אֹתוֹ
Ish ish ki yihyeh tamei lanefesh o bederekh rehoqah lakhem, o ledoroteikhem, ve-asah pesah ladonai; bahodesh hasheni be-arba'ah asar yom, bein ha-arbayim, ya-asu oto.
When any of you or of your posterity who are defiled by a corpse or are on a long journey would offer a passover sacrifice to the Lord, they shall offer it in the second month, on the fourteenth day of the month, at twilight. (Numbers 9:10-11)
Curiously, this is the only holiday of the seven identified in the Torah that have a special sacrifice for which this is possible. Perhaps Pesah was so important to our ancestors, given that it held the foundational narrative of the Israelite nation, that it warranted another opportunity.
The conclusion, say the rabbis, is that we are offered a second chance; the Talmud reads "on a long journey" to also mean one who might have strayed off the path, and Pesah Sheni is an opportunity to return. And yet, if only for Pesah, doesn't that suggest that these opportunities are not always available? We have to take them when they come.