Do you want it? Do you have the means to buy it without getting into debt? If the answer to both of these is yes, just do it. You’ll only be annoyed at yourself if you don’t.
If everyone only ever bought what they “need” we’d all be riding around on shitty bikes, and wearing clothes from Asda* Ie. The world would be a f**king boring place.
Case in point, I’m about to hit 30 and just bought a skateboard the other week. Haven’t ridden one well in over 10 years, and probably won’t use it that much, but I wanted it (through some misguided sense of nostalgia) and had the means to buy it, so thought **** it, why not?
If you’re not convinced, wait a while; the frame’s not going anywhere.
*not that there is anything wrong with cheap bikes and clothes from Asda- they work, and will do for 99% of people, but they’re both definitely a bit dull…