Much of our behavior patterns can be attributed to our surrounding environment and influences.
Take the term “Mesiras Nefesh”. What does it mean to sacrifice for Hashem? Consider a woman who goes out to work so that her husband can learn full time in Kollel. For many, this would constitue and act of Mesiras Nefesh. However, some women may tell you that for them, the ability to leave the house and the kids for awhile is “Chayei Nefesh – Enjoyment”! Consider the term “Masmid”. Today, if a bachur gets up early and learns for 3o minutes before davening, he is considered a “masmid”. However, in previous generations, hasmada was subject to a totally different standard and was categorized by someone who learned for hours on end! So who is the one who is truly a masmid and who is the one who is truly moser nefesh? The answer is that both examples are correct..and it is simply a matter of the environment in which you live. Therefore, although there are many ‘examples’ of mesiras nefesh, I would say that if you had to apply a definition to the term, it would be a persons’ desire and sacrifice to break a specific pattern of (their) life and to take a step up and a step forward in their avodas Hashem!
<Heard from Rav Shimshon Pincus>
Thats not just logic. Thats really sseibnle.