I totally agree with this. Tech waves can come and go so quickly that you could be obsolete before you even finish building something with the popular tech stack from last month (ok, a bit of hyperbole, but it sometimes feels like new things replace the last new thing before you even know why you would need the thing in the first place).

Not only do you need to try and save as much as possible (which is really hard if you are not single and able to live with roommates), you need to be constantly learning.