I don't think it's wise idea to invest in a coin only by looking the previous ATH, because there's no guarantee the coin will comeback or beat the previous ATH, it's not like Bitcoin.

Doge price was increase because Elon Musk trolled in Twitter and people take it as serious, so many people want to buy Doge. If Elon Musk stop to troll about Doge, Doge price will not increase a lot, just like in 2017/2018.